Influenza vaccine hesitancy is a significant threat to global efforts to reduce the burden of seasonal and pandemic influenza. Potential barriers of influenza vaccination need to be identified to inform interventions to raise awareness, influenza vaccine acceptance and uptake.
This review aims to (1) identify relevant studies and extract individual barriers of seasonal and pandemic influenza vaccination for risk groups and the general public; and (2) map knowledge gaps in understanding influenza vaccine hesitancy to derive directions for further research and inform interventions in this area.
Thirteen databases covering the areas of Medicine, Bioscience, Psychology, Sociology and Public Health were searched for peer-reviewed articles published between the years 2005 and 2016. Following the PRISMA approach, 470 articles were selected and analyzed for significant barriers to influenza vaccine uptake or intention. The barriers for different risk groups and flu types were clustered according to a conceptual framework based on the Theory of Planned Behavior and discussed using the 4C model of reasons for non-vaccination.
Most studies were conducted in the American and European region. Health care personnel (HCP) and the general public were the most studied populations, while parental decisions for children at high risk were under-represented. This study also identifies understudied concepts. A lack of confidence, inconvenience, calculation and complacency were identified to different extents as barriers to influenza vaccine uptake in risk groups.
Many different psychological, contextual, sociodemographic and physical barriers that are specific to certain risk groups were identified. While most sociodemographic and physical variables may be significantly related to influenza vaccine hesitancy, they cannot be used to explain its emergence or intensity. Psychological determinants were meaningfully related to uptake and should therefore be measured in a valid and comparable way. A compendium of measurements for future use is suggested as supporting information.
Citation: Schmid P, Rauber D, Betsch C, Lidolt G, Denker M-L (2017) Barriers of Influenza Vaccination Intention and Behavior – A Systematic Review of Influenza Vaccine Hesitancy, 2005 – 2016. PLoS ONE 12(1): e0170550. https://doi.org/10.1371/journal.pone.0170550
Editor: Benjamin J. Cowling, University of Hong Kong, HONG KONG
Received: November 3, 2016; Accepted: January 6, 2017; Published: January 26, 2017
Copyright: © 2017 Schmid et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information files. Additionally, a full list of analyzed research articles and determinants as well as a full list with excluded papers and reasons for exclusion are available for download from the OSF database (URL osf.io/y83z7).
Funding: This project was financed by the World Health Organization Headquarters, Geneva (WHO Registration Nr. 2015/592427-0; Reg. File TTi-15-APW-13). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Influenza is a significant health threat in our world today. For instance, seasonal influenza alone leads to an estimated 3 to 5 million cases of severe illness, and about 250,000 to 500,000 deaths globally each year . Most deaths associated with influenza occur among the most vulnerable members of the world population, i.e. very young children, the elderly and chronically ill patients. Despite influenza’s severity and the availability of safe vaccines, low influenza vaccine uptake rates within specific risk groups remain a challenge throughout the globe and contribute to the burden of disease . The scope of the issue became particularly clear during the 2009–2010 H1N1 pandemic . Vaccine uptake in the general public was very low, with countries reporting less than 50% of the expected coverage in target populations all over the globe (; Europe:  China: ; Australia: ; USA: ). Even more worrying is the fact that vaccine uptake in high risk groups, such as pregnant women  and the elderly , were similarly low.
Influenza vaccine hesitancy
In recent years, several researchers have focused on identifying potential barriers to vaccine acceptance [10–12]. Foremost, the WHO SAGE working group defined the concept of vaccine hesitancy. Vaccine hesitancy describes the acceptance of vaccines on a continuum between demand and no demand ranging from accepting all vaccines to accepting no vaccine . According to their work, “vaccine hesitancy refers to a delay in acceptance or refusal of vaccination despite availability of vaccination services. Vaccine hesitancy is complex and context specific, varying across time, place, and vaccines” . This definition of vaccine hesitancy suggests that barriers to vaccine uptake can be very different in kind and significance, with regard to the vaccine and disease in focus. Influenza vaccines, as compared to other standard vaccines, have some special characteristics that should also be considered when looking at influenza vaccine hesitancy. Namely, vaccine effectiveness varies annually and is frequently low [14,15]. Vaccination is required annually; in most countries it is recommended for specific risk groups only and there are influenza-specific myths (e.g. the flu shot can cause the flu ). Thus, influenza vaccine hesitancy has unique features that justify further investigations in order to gain a specific understanding of the phenomenon.
Previous systematic reviews on predictors of influenza vaccine uptake within certain risk groups provide initial insights to understand influenza vaccine hesitancy (pregnant women ; elderly ; healthcare personnel [19,20]; general public ). However, different methodologies regarding the search strategies and literature selection criteria complicate comparisons and synthesis of results between risk groups. Moreover, potential differences between predictors of pandemic and seasonal influenza within one risk group are, except for pregnant women , not addressed by previous reviews. Lastly, and to the best of the authors’ knowledge, systematic reviews on influenza vaccine hesitancy for children and chronically ill individuals do not exist. The present systematic review bridges the gap between the general analysis of vaccine hesitancy delivered by the SAGE working group  and other systematic reviews that concentrate on one risk group and one flu type only [18–21]. Furthermore, it integrates data on children and chronically ill individuals. With this approach we aim to gain a better understanding of influenza vaccine hesitancy as a broader concept for all relevant risk groups and influenza types. To support this goal, we applied a comprehensive search strategy that is unprecedented in research about influenza vaccine hesitancy.
Models of vaccine hesitancy
There are several levels at which we can analyze vaccine hesitancy. On the meso-level, the SAGE working group proposed in their model that individual/social influences, contextual influences and vaccine and vaccination-specific issues play a role [10,13]. It is further broken down and described as being “influenced by factors such as complacency, convenience and confidence” [10,13] as well as calculation on the macro-level . High complacency implies that “…general involvement in the decision is low because complacent individuals do not feel threatened by infectious diseases” . Low convenience (or inconvenience) can emerge because “attitudes are not strongly against or in favor of vaccination in this case, which means that vaccination is not important enough to actively overcome barriers. Consequently, when decision-makers face barriers such as lack of access, cost, or travel time, they decline vaccination to avoid these barriers” . A lack of confidence usually emerges due to “strong negative attitudes towards vaccination (in contrast to the complacency and convenience types)” . This in turn is correlated with the belief in misconceptions about the vaccine and the disease because knowledge “is likely to be distorted by misinformation about risks posed by vaccination or by affiliation to certain social groups close to the anti-vaccination movement” . Calculation plays a role when “individuals do not have a strong pre-existing attitude towards vaccination but base their decisions on utility maximization, which leads to vaccination or non-vaccination, depending on the subjective evaluations of risks.” .
On the micro-level, the model can be further specified and characterized by psychological profiles that refer to psychological theories of health decision-making and behavior , such as the Theory of Planned Behavior (TPB; ). These models provide psychological insights that contribute to our understanding of why some individuals get vaccinated while others refuse to do so. They define the potential barriers to vaccine uptake on a concrete and measurable level, and specify the interrelation between the variables. TPB describes health behavior as a function of the behavioral intention to show a certain behavior (e.g. vaccination). The intention is a function of an individual’s attitude (negative or positive evaluation of behavior and outcome), perceived behavioral control (PBC; perceived ability to perform a behavior) and the subjective norm (perceived social pressure of significant others). Literature about social norms distinguishes between injunctive norms (i.e. what significant others think one should do) and descriptive norms (i.e. what significant others do). In the TPB, subjective norms are injunctive norms, defined as the product of normative beliefs (what others think one should do) and one’s motivation to comply with these beliefs. Based on a meta-analysis Revis and Sheeran suggest to also include descriptive norms in the TPB to increase its predictive power . Other extensions of the TPB have also shown an increase in the predictive power of the theory by integrating concepts of risk perception , past behavior , knowledge , and experience  into the model. TPB thus reliably predicts various health behaviors, such as vaccinating, condom use, or physical activity .
In this review we will analyze vaccine hesitancy on the macro- and micro-level. The results section reports the barriers to influenza vaccination on the micro-level for different risk groups and across influenza types. We use an extended version of TPB as a comprehensive theoretical framework for identifying and clustering barriers to influenza vaccination that have been identified during the past decade. As this review aims to integrate all potentially relevant barriers rather than psychological processes alone, we also include physical, contextual, and sociodemographic aspects to the conceptual framework [10,13]. This enhanced framework is displayed in Fig 1. In the discussion section we will integrate the findings on the macro-level and discuss hesitancy profiles of the different risk groups, also regarding potential differences of seasonal vs. pandemic influenza within these groups.
Determinants are based on empirical and theoretical work from Ajzen , Schmiege et al. , Rhodes & Courneya , Koo et al. , Pomery et al. , Larson et al. . Significant determinants from 470 research articles are clustered according to the model. Circle size represents the total number of reported incidents.
Goals of the present review
With this framework the systematic review identified relevant studies on influenza vaccine hesitancy published between 2005–2016 to address the following research goals:
- to extract individual barriers to seasonal and pandemic influenza vaccination for risk groups and the general public;
- to map knowledge gaps in understanding influenza vaccine hesitancy and to derive directions for further research and interventions in this area.
A comprehensive understanding of influenza vaccine hesitancy in different risk groups and under different circumstances (seasonal vs. pandemic) is necessary to develop evidence-informed strategies and research to increase coverage of seasonal influenza vaccines. The review contributes to the 2016 consultation on the Global Action Plan for Influenza Vaccines (GAP). One of the objectives of the GAP is to increase the seasonal uptake of influenza vaccines to improve pandemic preparedness . WHO has launched GAP in order to reduce the threat and burden of influenza for individuals and populations alike.
Search and selection procedure
This review uses databases in the areas of Medicine, Bioscience, Psychology, Sociology and Public Health, in order to capture the great variety of aspects that define influenza vaccine hesitancy. The search was also extended to Global Index Medicus (GIM) libraries  that provide health literature produced by low- and middle-income countries. These libraries help to identify research from areas that are under-represented in research about vaccine hesitancy . The final search included the following databases:
Table 1 shows the search terms used in this review. From these, a broad search string was first developed for PubMed (see S1 Table) and then adapted to all other databases. Guided by previous systematic reviews, we included terms in the review that relate to the broader concept of vaccine hesitancy (; e.g. acceptance, demand, refusal), and specify more detailed psychological terms ([4,19,21,32]; e.g. attitude, knowledge, belief). Furthermore, terms that appear in a broader policy-oriented discussion of vaccine hesitancy were also included (; e.g. policy, mandatory, trust).
Terms regarding influenza and its prevention by vaccination were added to the resulting list of search terms to specify the search (columns 1 and 2 in Table 1). Thus, the search included results that were about influenza AND vaccines AND one of the hesitancy indicators specified in the remaining five columns of Table 1. The publication dates of interest were limited to the period between 01.01.2005 and 18.01.2016.
The initial search was conducted from 18.01.2016 to 12.02.2016. The analysis followed the PRISMA-approach  displayed in Fig 2. After duplicates were removed, all remaining articles were first scanned by title and abstract. Then, articles were excluded according to the a priori exclusion criteria which are displayed in Table 2. Since the focus of the review was on barriers to human influenza vaccine uptake or intention, reasons for exclusion were: not addressing human influenza vaccine, content not related to determinants of influenza vaccine hesitancy (e.g. studies about effectiveness of the vaccine), determinants not linked to a behavioral outcome. To ensure quality of results articles that were not peer-reviewed were excluded. To avoid the risk of including the same study twice and to avoid issues with conflicting exclusion criteria, other review articles and meta-analysis with no primary data were excluded. Because modeling studies and intervention studies were not the focus of this review, they were excluded. Due to language barriers, articles not in English or German were also excluded. Most databases provided filters for the exclusion criteria year of publication (2005–2016), species in focus (human) and type of publication (journal article). If applicable, these filters were used during the initial search.
The resulting articles were coded by year of publication, WHO region, risk group, influenza type, outcome variable (intention or behavior), and type of analysis (multivariate vs. other). The category other includes studies that used univariate analysis (models including only one independent predictor), correlative studies and qualitative studies. To acknowledge the multidimensional nature of vaccine decision-making and to increase validity of reported barriers, only articles using multivariate analysis were further analyzed (see also ). From the remaining studies, all significant predictors of influenza vaccine uptake or intention (p-value < .05) were extracted and documented.
Coding and operationalization of vaccine hesitancy
Vaccine hesitancy is thus operationalized as low influenza vaccine uptake or low intentions to vaccinate against influenza. Therefore, each predictor is coded as a barrier, i.e. as a determinant that decreases uptake or intentions. When lower age, for example, is related to lower uptake or lower intentions, lower age is coded as a barrier. When publications reported that higher age was associated with higher uptake, i.e. when it was framed as a “promoter” of vaccine uptake, we re-coded this so that lower age again corresponds with lower vaccine uptake. Only when the opposite result was found, e.g. lower age was related to higher uptake in one study and with lower uptake in another study, we coded age both as a promoter and a barrier. In cases of a non-linear trend, the association between the determinant and the outcome were coded as inconclusive (e.g. when individuals with highest and lowest age had significantly lower uptake rates than middle-aged groups). Additionally, for each study it was coded whether the intention to vaccinate or actual vaccine uptake was assessed.
Overall, 29,630 records were identified using the described search strategy (Table 1) in the relevant databases described above. After removing duplicates, 13,575 articles were further screened by title and abstract (Fig 2). 12,483 papers were removed according to the exclusion criteria (Table 2). 1,092 articles were eligible for the full-text analysis. After full-text analysis, 590 articles were removed (Fig 2 for specific reasons). If a full article could not be found in any database used in this review, then authors were contacted and asked for access. This procedure was not successful in 32 cases. The remaining 470 articles were considered for descriptive analysis and synthesis.
Descriptive analysis of articles
Research about barriers to influenza vaccine uptake was conducted in all WHO regions. However, most of the research focused on Western samples (Americas 199/470; Europe 176/470; Western Pacific 75/470; Eastern Mediterranean 12/470; Africa 5/470; South Eastern Asia 5/470). The majority of research did not focus on a specific risk group but addressed the general public (191/470). The most studied risk group was healthcare personnel (includes healthcare and non-healthcare occupations; e.g. administrative staff), while children between 6 and 59 months of age were the least studied group (Health Care Personnel 117/470; Elderly 62/470; Chronic Condition 45/470; Pregnant Women 35/470; unspecified22/470; Children 18/470). This trend is consistent over time and region. The largest proportion of research focused on seasonal influenza (331/470; pandemic influenza 156/470; avian influenza 5/470; unspecified 3/470). Actual vaccine behavior was the main outcome variable in the majority of the studies (377/470), while the intention to vaccinate against influenza was assessed in 100 of the 470 studies (unspecified 4/470). When the outcome was not specific for only one flu type, region, risk group or outcome (e.g. paper focused on pandemic and seasonal influenza but results were merged), then the publication was coded as unspecified. When a publication matched more than one category within a variable (e.g. when a study measured uptake and intention), then the publication was included in all separate descriptive analyses (e.g. for intention and behavior).
Fig 3 shows that over time the number of published studies about influenza vaccine hesitancy increased. There are peaks in the numbers of published articles after the avian influenza outbreak 2005, particularly in the Americas and European regions, and after the influenza pandemic 2008/2009 in the Americas, European and Western Pacific regions. The number of publications from authors from the African, South East Asian and Eastern Mediterranean regions remains low throughout the entire period.
Micro-level analysis of determinants
After full-text analysis of all 470 articles, 258 independent barriers to influenza vaccination were identified. In order to identify the most relevant barriers, we counted the number of studies that found this barrier. The mean number of studies per barrier was M = 8.3, SD = 19.2. 104 barriers were significant in only one study. Due to the large quantity of identified variables, we introduced a cut-off criterion by including only those variables that were reported as significant barriers in at least 6 studies. This led to a total number of 72 barriers.
Fig 1 illustrates the number of significant results found in each category. The larger the size of the circles, the higher the number of significant results. The following micro-level analysis of influenza vaccine hesitancy provides information about the occurrence of each of the barriers in the different risk groups. The Supporting Information section additionally provides an illustration of all 72 predictors as increasing or decreasing factors of vaccination, stratified for each risk group and flu type (S1–S13 Figs). As the results for intention and uptake are highly similar, we have aggregated the results and refer to both outcomes as vaccine uptake.
The utility of vaccination is a function of benefits and risks associated with vaccination (e.g. issues around vaccine safety). Benefits arise through protection from disease, i.e. the perception of disease risk. Additionally, vaccination entails a social benefit through herd immunity. In terms of measurement, research about risk perception differentiates between risk as analysis  vs. risk as feelings . The former is measured as a combination of perceived severity of the disease or vaccine-adverse events (VAE) and the probability of getting the disease/VAE . The latter is the result of emotional concern, which was previously operationalized as worry about risk of the disease/VAE and anticipated regret of (not) receiving the vaccine .
Perceiving low risk of the disease was identified as a barrier to influenza vaccine uptake in most risk groups and the general public (HCP 18/117 [39–56]; Pregnant 1/35 ; Chronic 1/45 ; Elderly 2/62 [59,60]; Public 12/191 [61–72]). For example, an Australian study found that among members of the general public the two most stated reasons for not accepting the vaccine were “situation is not serious enough” and “I am not at risk” . In line with this, the cognitive parameters of risk perception were frequently identified as significant barriers, i.e. perceiving the likelihood of getting the disease as low (HCP 4/117 [43,73–75]; Pregnant 1/35 ; Elderly 1/62 ; Public 9/191 [68,72,78–84]) and perceiving the severity of the disease as low (HCP 8/117 [44,85–91]; Pregnant 3/35 [92–94]; Chronic 3/45 [58,95,96]; Children 2/18 [97,98]; Elderly 4/62 [96,99–101]; Public 16/191 [65,71,72,81,83,99,102–111]). Additionally, perceiving oneself as less susceptible to the disease decreased the uptake of the influenza vaccine in 23 studies (HCP 4/117 [42,112–114]; Pregnant 3/35 [115–118]; Chronic 1/45 ; Children 1/18 ; Elderly 1/62 ; Public 11/191 [99,107,108,120–128]).
Of all 470 studies, 42 reported affective parameters of risk perception as significant barriers to influenza vaccination, i.e. low worry about the disease (HCP 7/117 [39,40,129–133]; Pregnant 3/35 [117,134,135]; Elderly 1/62 ; Public 24/191 [61–64,79,102,120,121,137–152]) and low anticipated regret in the case of not being vaccinated (HCP 1/117 ; Pregnant 1/35 ; Public 5/191 [78,154–157]). For example, Tucker et al. report that pregnant women in a US sample who worried about influenza were approximately 3 times more likely to get the flu vaccine even when adjusting for cognitive risk parameters like probability and susceptibility of the disease .
Cognitive and affective risk perceptions regarding the vaccine were also reported as a barrier to influenza vaccination. Specifically, higher perceived risk of vaccine adverse events was found to decrease vaccine uptake (HCP 7/117 [41,158–163]; Pregnant 5/35 [94,164–167]; Chronic 2/45; Children 1/18 ; [58,96]; Elderly 3/62 [96,136,168]; Public 9/191 [66,83,109,111,169–173]), as was general worry about the safety of the vaccine (HCP 15/117 [44,45,53,56,75,87,90,112,130,132,159,163,174–176]; Pregnant 6/35 [92,94,117,167,177,178]; Elderly 1/62 ; Children 2/18 [179,180]; Public 14/191 [66,103,137–139,154,169,172,173,181–185]). For example, in an Australian study beliefs like, "1) the vaccine had been rushed through; 2) there had been insufficient research; 3) the vaccine had not been tested adequately"  were among the expressions of concern regarding the safety of the vaccine.
Of all 470 studies, 29 identified the social benefit as a significant influence on influenza vaccine uptake. The social benefit of vaccination is often used as an ethical argument for HCP to get vaccinated . Thus, most studies in this section pertain to HCP. Individuals who did not acknowledge the social benefit of the vaccine were less likely to vaccinate (HCP 3/117 [86,89,187]; Public 3/191 [128,188,189]). When healthcare personnel lacked the belief that getting vaccinated protects patients (HCP 5/117 [45,53,161,187,190]) or relatives (HCP 2/117 [161,187]) vaccine uptake was lower; the same was found for pregnant women regarding their unborn child (1/35 ). Moreover, when individuals perceived low risk for others due to influenza, their uptake was lower (HCP 3/117 [86,89,187]; Public 6/191 [61,66,140,141,191,192]). The perception that there is low risk of transmitting the disease to others also decreased uptake (HCP 8/117 [43,44,46,55,75,158,175,193]). Variables referring to the social benefit of vaccination were not reported as a significant influence for the elderly, chronically ill patients and children under 5 years of age.
When individuals perceived low pressure of significant others to get vaccinated, vaccine uptake was lower than when social pressure was high (HCP 4/117 [88,91,153,194]; Pregnant 1/35 ; Chronic 2/45 [196,197]; Public 10/191 [66,111,124,155,157,198–202]). In some studies the descriptive norm (the belief about what others do) was related to higher uptake (HCP 2/117 [203,204]; Pregnant 1/35 ). Yet other studies reported a lower normative influence, based on a score that includes injunctive norms, i.e. the belief in what others think one should do, and descriptive norms (Children 1/18 ; Public 5/191 [206–210]), as a barrier to vaccine uptake. For HCP, vaccine uptake was lower when they lacked the belief that the vaccine was an ethical or professional obligation (10/117 [48,194,211–218]). For example, a Dutch study found that HCPs had a lower likelihood of getting vaccinated when they did not acknowledge that it was their duty to do no harm and to ensure continuity of care . In the general public, one study assessing subjective norms was inconclusive  and one experimental study found free-riding behavior in a hypothetical setting, i.e. declining vaccination uptake with an increasing number of vaccinated individuals .
Perceived behavioral control.
6 articles found that lacking perceived behavioral control was a significant barrier to vaccine uptake (Public 5/191 [124,155,199,200,220]; Unspecified 1/22 ); as was low self-efficacy (HCP 1/117 ; Elderly 1/62 ; Children 1/18 ; Public 5/191 [124,209,210,224,225]). For example, a study by Hilyard et al. found that “parents were 1.3 times more likely than others to get their children vaccinated for every standard deviation increase in self-efficacy” .
Having a negative attitude towards the influenza vaccine was a major barrier to vaccine uptake (HCP 7/117 [153,161,227–231]; Pregnant 6/35 [92,232–236]; Chronic 4/45 [197,237–239]; Elderly 1/62 ; Public 17/191 [12,65,124,128,143,155,198–200,202,220,240–245]). Moreover, individuals who did not believe in the effectiveness of the vaccine showed lower vaccine uptake in every risk group (HCP 11/117 [44,46,48,75,86,130,161,190,194,211,246]; Pregnant 5/35 [76,116,195,235,247]; Chronic 4/45 [58,96,248,249]; Children 1/18 ; Elderly 1/62 [96,99,100,136,251–253]; Public 23/191 [61,65–67,81,99,102,104,105,109,121,144,156,169,173,181,185,199,224,254–257]). In one study about maternal influenza immunization decision-making, Frew et al. note that “a woman who believed the vaccine was highly effective had a 30% to 60% increase of likelihood of later obtaining it” . Additionally, a lack of trust in authorities such as the National Health Service (NHS) was reported to hinder immunization (1/117 HCP ; Pregnant 2/35 [117,167]; Elderly 1/62 ; Public 20/191 [63,81,101,108,120,122,141,142,147,172,173,191,198,201,259–264]).
Individuals who had already been vaccinated against influenza in previous seasons showed higher vaccine uptake in all risk groups (HCP 43/117 [42,44,50,51,54,74,75,86,87,112,113,160,161,190,193,214,216,230,265–289]; Chronic 9/45 [197,248,249,290–295]; Pregnant 10/35 [76,93,115,116,167,178,195,296–298]; Children 2/18 [223,299]; Elderly 7/62 [100,168,258,300–303]; Public 50/191 [62,66,69–72,81,99,101,103,125,140,143,145,146,150,152,157,169,170,172,173,183,191,192,198,209,219,224,240,254,256,259,303–320]). These findings mirror the results of previous systematic reviews that have repeatedly identified past behavior as a strong predictor of influenza vaccine acceptance [18,19,21]. Additionally, uptake of influenza vaccine was positively related to uptake of pneumococcal vaccination in chronically ill patients and the elderly (4/45 [290,291,295,321]; elderly (1/62 ).
9 studies related the experience of sickness to vaccine uptake: individuals who had not suffered from influenza previously were less likely to be vaccinated in upcoming seasons (HCP 4/117 [75,230,273,323]; Pregnant 1/35 ; Chronic 1/45 ; 1/18 Children ; Public 2/191 [326,327]). In one study, however, HCP who had been infected with H1N1 were less likely to get vaccinated . This finding could be explained by the fact that participants believed they had already been infected with the very same strain the vaccine protects against. In the healthcare context, 5 studies noted fewer years of professional experience as a barrier to vaccine uptake in HCP (5/117 [194,285,328–330]). For example, Looijmans van den Akker et al. found lower vaccine uptake when HCPs had worked in healthcare for less than 15 years ; Dönmez et al. reported lower vaccine uptake for physicians who had worked for less than 5 years .
In all risk groups as well as the general public, lacking general knowledge about influenza and the vaccine was identified as a barrier (HCP 11/117 [41,51,53,131,277,285,328,331–334]; Pregnant 4/35 [93,233,236,335]; Chronic 2/45 [238,325]; Children 1/18 ; Elderly 1/62 ; Public 9/191 [110,314,326,337–342]). Examples of knowledge are modes of transmission of the disease and medical exemptions for vaccination. For HCP a lack of influenza-specific education, such as influenza-related training or education materials, was a barrier to vaccine uptake (5/117 [52,131,272,283,343]). The belief in misconceptions, i.e. agreement with specific false statements, was reported as a barrier for HCPs (4/117 [46,161,273,344]) pregnant women (2/35 [117,167]), chronically ill individuals (1/45 ), the elderly (1/62 ), and the general public (2/191 [220,255]). The majority of articles report the myth that the vaccine can cause the flu as a significant barrier. For pregnant women, misconceptions regarding the safety of the vaccine for the fetus, e.g. the increased chance of miscarriage or birth defects, were reported as a definitive barrier . Additionally, one study reported an increase in vaccine uptake when individuals wrongly believed that the vaccine protects against the common cold .
Several studies have found that unhealthy lifestyles have a negative impact on vaccine uptake, such as alcohol consumption (Chronic 1/45 ; Public 3/191 [345–347]) and smoking habits (Pregnant 3/35 [296–298]; Chronic 11/45 [95,249,321,325,348–354]; Elderly 9/62 [346,350,355–361]; Public 9/191 [317,346,347,361–366]). However, smoking was also a promoter in some cases (HCP 1/117 ; Public 3/191 [72,192,368]), and alcohol consumption did not reveal a clear picture in the reviewed studies (Pregnant 1/35 ; Elderly 1/62 ; Public 2/191 [346,365]). More consistently, having given up smoking was reported to increase the uptake of vaccination (HCP 2/117 [367,369]; Chronic 4/45 [321,370–372]; Elderly 3/62 [346,361,373]; Public 6/191 [192,318,346,347,373,374];). The relationship between these rather proximate health variables and vaccine uptake “may be explained by confounding factors, such as health status, attitudes regarding immunization and physician’s perspective of smokers’ health, so this association should be interpreted with care” .
The results concerning the level of physical activity and one’s own perceived health status are similarly mixed. Decreased physical activity was reported as a barrier to vaccination in some cases (HCP 1/117 ; Elderly 2/62 [361,375]; Chronic 1/45 ; Public 4/ 191 [316,347,361,365]), and as a promoter in others (Chronic 1/45 ; Public 1/191 ). When individuals perceived their own health status as good they were less inclined to vaccinate (Chronic 5/45 [321,350–352,371]; Elderly 6/62 [350,355,361,376–378]; Public 7/191 [360,361,374,377,379–381]). This correlation, however, was reversed in a few other studies (Chronic 1/45 ; Elderly 2/62 [383,384]; Public 2/191 [338,363]).
Further consistent barriers to influenza vaccine uptake were a lower body mass index (Chronic 1/45 ; Elderly 2/62 [346,366]; Public 2/191 [346,366]) and not having a pre-existing medical condition (Chronic 5/45 [370,385–388]; Children 1/18 ; Elderly 3/62 [253,366,390]; Public 7/191 [137,169,253,257,264,319,380]).
On the meso-level, the SAGE model acknowledges the influence of external contextual factors on vaccine uptake. We will differentiate between specific access issues (e.g. financial costs), interaction with healthcare system that can facilitate a vaccine decision  (e.g. having a regular source of care), cues to action as external triggers of vaccine behavior  (e.g. recommendation), and system factors that have been discussed as direct influences of healthcare utilization  (e.g. size of care facility can influence time of care per patient). All of these contextual factors describe potential external barriers that affect the ease of getting an influenza vaccine.
General access to influenza vaccines due to political, geographical or economic issues influencing production and reliability of supply was not identified as a barrier to vaccination in this review. From the 470 studies reviewed, none reported a general lack of access to vaccines as a significant barrier to vaccine uptake. However, getting the vaccine was reported as inconvenient for HCPs (6/117 [42,45,56,86,88,393]), chronic patients (1/45 ), children (1/18 ) and the elderly (1/62 ). Matsui et al. note that “subjects described these barriers/inconveniences as means of transportation to a clinic, physical disability, and the expense of vaccination per se” . Concrete financial expenses were reported as a barrier for HCPs (9/117 [91,112,160,215,273,285,343,394,395]), children (1/18 ) and the general public (7/191 [111,181,224,254,340,396,397]). For example, Kelly et al. found that among Australian students who were eligible for government-funded vaccines, the likelihood of getting the vaccine was 7 times higher than for individuals who were ineligible for funding .
Interaction with healthcare system.
Individuals who interact less frequently with the healthcare system, e.g. fewer doctor visits  or hospitalizations in a given timeframe , had a lower likelihood of getting vaccinated (Pregnant 2/35 [324,398]; Chronic 12/45 [95,249,290,294,321,325,349,350,352,353,399,400]; Children 5/18 [119,401–404]; Elderly 21/62 [59,251,300,302,322,350,356–358,375,376,390,405–413]; Public 13/191 [61,255,304,347,405,414–421]). In line with these findings, not having a regular source of care (e.g. primary care physician) hindered vaccine uptake in most risk groups (HCP 2/117 [369,422]; Pregnant 1/35 ; Chronic 1/45 ; Elderly 3/62 [405,406,423]; Public 6/191 [192,264,363,368,405,424]).
Cues to action.
Individuals who did not receive a direct recommendation from medical personnel were frequently reported to be less likely to vaccinate (HCP 5/117 [75,161,215,422,425]; Pregnant 15/35 [57,76,92,93,115,116,167,177,232–235,426–428]; Chronic 7/45 [58,248,291,292,429–431]; Children 6/18 [98,179,180,299,389,432]; Elderly 8/62 [96,100,136,222,300,322,407,433]; Public 11/191 [66,109,125,170,257,305,366,434–437]). The same was true for individuals who did not receive a recommendation from relatives (Elderly 3/62 [162–164]; Public 3/191 [103,125,219]).
The size of a healthcare facility (hospital, nursery home, practice) can impact vaccine uptake of patients, residents, or HCP employed in the facilities. 6 studies identified the size of the care facility as a significant factor for vaccine uptake. For HCPs, the results are rather inconclusive, with one study reporting increased size as a barrier (1/117 ) and 2 studies reporting it as a promoter (2/117 [438,439]). For patients and residents, an increased size of care facility was consistently noted as a barrier (Elderly 1/62 ; Public 2/191 [440,441]).
People who lived in the most socioeconomically deprived areas (1/45 Chronic ; 1/62 Elderly ; 2/191 Public [442,443]) or visited a practice in such areas (1/62 Elderly ) were identified as being less likely to receive influenza vaccination than people from wealthier areas.
Most sociodemographic factors present a mixed picture of results. As such, higher age was reported as a barrier to vaccine uptake (HCP 5/117 [53,54,89,285,331]; Chronic 3/45 [291,431,445], Children 3/18 [97,402,446]; Public 8/191 [72,108,224,309,396,447–449]) but also as a promotor (HCP 30/117 [45,46,51,55,75,91,131,133,274,280,289,323,374,450–465]; Pregnant 3/35 [57,297,324]; Chronic 21/45 [95,238,290,294,321,325,349–354,370–372,386–388,399,466–468]; Children 2/18 [119,205]; Elderly 21/62 [59,96,168,303,350,356,358,359,361,366,375,376,405,409,410,412,423,469–471]; Public 57/191 [61,63,68,69,71,83,120,122,142,145,147,155,172,241,255,264,303,306,307,312,313,316,318,341,347,360–363,366,368,374,380,381,384,397,401,405,415–418,435,441,471–483]). Moreover, some studies show inconclusive results regarding the influence of age (Chronic 1/45 ; Children 1/18 ; Elderly 2/62 [302,485]; Public 7/191 [105,148,152,307,311,419,486];). An even more inconclusive pattern can be observed for gender and ethnicity. Being female was noted as a barrier (HCP [50,51,53,133,279,283,289,425,451,453,458,487]; Chronic 7/45 [238,321,352–354,372,442]; Elderly 7/62 [59,301–303,322,346,485]; Public 21/191 [65,68,72,105,122,146,148,240,256,261,308,310,311,345,346,374,416,417,449,479,488]), as a promoter (HCP 10/117 [114,190,204,277,285,328,331,455,462,463]; Chronic 6/45 [96,249,370,466,489,490]; Elderly [96,366,423,491,492]; Public 19/191 [61,63,150,192,306,318,347,361,363,364,366,381,384,405,414,443,473,482,493]), and as inconclusive (Chronic 1/45 ; Public 2/191 [303,486]). Being white was reported as a barrier (Public 3/191 [70,137,494]) and somewhat more frequently as a promoter (HCP 3/117 [333,465,495]; Chronic 1/45 ; Children 1/18 ; Elderly 7/62 [361,405,409,469,496–498]; Public 7/191 [147,189,361,405,414,477,499]). The reasons why these variables either decrease or increase vaccine acceptance are rarely explained.
Living alone (Elderly 5/62 [59,168,375,470,500]) and being unmarried (Elderly 5/62 [350,355,360,361,469]; Public 5/191 [62,150,192,365,384,501]) was negatively associated with vaccine uptake. Nagata et al. (2013) mention that this relation may be mediated by access and cues to action: “people who live alone with limited assistance may have less access, irregular preventive health visits, and less support from family members” . A limited number of other studies, however, found an inverse relationship of marital status and vaccination (Pregnant 1/35 ; Public 1/191 ). The results of the latter study by Frew et al. (2014) indicate that pregnant women who are single, divorced, or widowed “may exert more control over their health and the health of the unborn child, as they are likely the primary providers for themselves and their unborn child” and thus vaccinate more .
On the micro-level, sociodemographic variables such as gender and age were the most reported, but also most inconsistent predictors of influenza vaccination. Besides this, lacking cues to action, low perceived utility of vaccination, a negative attitude towards influenza vaccines, and fewer previous influenza vaccinations were most frequently and consistently identified as significant barriers to influenza vaccination. In the following discussion we will first discuss differences between pandemic and influenza vaccine hesitancy and then summarize the evidence for each risk group stratified for pandemic and seasonal influenza vaccination. In doing this, we will first summarize the most important micro-level determinants and then synthesize the results based on the macro-level model of vaccine hesitancy. The macro-level synthesis intends to inform the design of future interventions to increase influenza vaccine uptake and thus supports our second research goal . Fig 4 gives a detailed overview of which barriers we allocated to which of the four hesitancy reasons, i.e. lack of confidence (e.g. negative attitude towards vaccines, decreased trust in authorities), complacency (e.g. decreased perceived risk of the disease, decreased worry about the disease), calculation (e.g. decreased belief: benefit of vaccines outweighs risks), and inconvenience (increased financial costs of vaccine, decreased frequency of interaction with healthcare service). Fig 4 also provides an overview of the findings collapsed across risk groups and influenza types. Fig 5 visualizes the number of significant results supporting each reason for hesitancy for each risk group and for pandemic (grey bars) and influenza vaccination (black bars).
Total numbers of studies reporting the variable as either decreasing (white) or increasing (black) vaccine acceptance or inconclusive (circled number).
Bars visualize the total number of significant results supporting each reason for hesitancy for each risk group. Grey bars indicate the absolute proportion of results addressing pandemic influenza uptake among the total results. Black bars indicate the absolute proportion of results for seasonal influenza uptake among the total results.
Seasonal vs. pandemic influenza vaccine hesitancy across all risk groups
Barriers for seasonal and pandemic influenza uptake were very similar in kind and reported relative frequency. For both influenza types, having missed the influenza vaccine in previous seasons was the most frequently reported barrier to vaccine uptake. Likewise, the relative number of reports about the influence of age and gender and additional risk factors (e.g. being elderly and having a chronic disease) were similar for pandemic and seasonal influenza.
However, differences occurred with regard to the 4C profiles. From the perspective of the 4C model, studies about seasonal influenza revealed a lack of confidence as the most frequently reported barrier of vaccine uptake (e.g. negative attitude, misconceptions about the disease or the vaccine). For pandemic influenza, complacency was the major barrier to vaccine uptake (e.g. low worry and perceived risk of the disease), followed by confidence (increased worry about the safety of the vaccine; distrust in authorities). In times of crisis, laypersons have few options other than to base their decisions on predictions provided by health authorities, i.e. trust and risk perceptions are highly influential determinants. A lack of confidence due to low perceived effectiveness of the vaccine was frequently reported as a barrier to vaccine uptake for both flu types.
Seasonal vs. pandemic Influenza vaccine hesitancy in HCP
For HCP, sociodemographic variables (age, gender, additional risk factors) and past behavior were among the most reported influences of seasonal as well as pandemic vaccine uptake. The profiles for pandemic and seasonal influenza vaccine hesitancy looked very similar (cf. S3 Fig and S4 Fig) with the exception that HCP who were not a physician showed lower uptake of the pandemic influenza vaccine.
On the macro-level, a lack of confidence was the major barrier to seasonal influenza vaccine uptake (due to decreased professional or ethical obligation to get vaccinated and misconceptions about the disease or vaccine). Additionally, complacency issues (decreased perceived risk of the disease) were also frequently reported. Inconvenience was the least reported reason.
For pandemic influenza vaccine uptake, complacency (decreased perceived risk of disease, decreased severity of disease, decreased worry about the disease) and lack of confidence (increased worry of safety of the vaccine) were similarly reported as prominent reasons for vaccine hesitancy in HCP.
Seasonal vs. pandemic influenza vaccine hesitancy in pregnant women
Past behavior, higher age, and recommendation from medical personnel were the most frequently reported predictors for seasonal influenza vaccine uptake. A lack of confidence was the most frequently reported barrier to seasonal influenza vaccine uptake for pregnant women (high perceived risk of the vaccine, high worry about safety of the vaccine, low perceived effectiveness of the vaccine and misconceptions about the disease or vaccine).
For pandemic influenza, not having received a recommendation from medical personnel was the most reported barrier to vaccine uptake. Similar to seasonal influenza vaccine hesitancy, a lack of confidence was the most frequently reported barrier to pandemic influenza vaccine uptake among pregnant women (negative attitude, high perceived risk of the vaccine, high worry of safety of the vaccine and low perceived effectiveness of the vaccine).
Seasonal vs. pandemic influenza vaccine in patients with chronic conditions
Previous behavior, smoking status and lower age were the most frequently reported barriers to seasonal influenza vaccine uptake among chronically ill patients. A lack of confidence due to a negative attitude and low perceived vaccine effectiveness and complacency issues (low perceived severity of disease) were the most reported barriers within the 4C framework for seasonal influenza.
For pandemic influenza, past behavior and higher age were also the most reported influences on vaccine uptake. Due to the low number of publications for chronically ill patients, on the macro-level only a lack of confidence due to misconceptions regarding the disease or vaccine were identified.
Seasonal and pandemic influenza vaccine hesitancy in children
Sociodemographic variables (age and education) and missing recommendations from medical personnel for the decision maker, i.e. parents of children between 6–59 months of age, were the most reported barriers to seasonal influenza vaccine uptake for children. With regard to the 4C model, calculation (decreased perceived own benefit of vaccine) and inconvenience (decreased frequency of interaction with health service) were the most prominent reasons for vaccine hesitancy.
For pandemic influenza, the only reported barriers in this under-researched risk group were complacency issues (decreased perceived severity of disease, not believing in the importance of the issue).
Seasonal vs. pandemic influenza vaccine hesitancy in the elderly
Sociodemographic variables (age, additional risk factors, education, gender), physical variables (smoking status, perceived health status) and past behavior were among the most reported barriers to seasonal influenza vaccine uptake. Especially for this risk group and in line with previous reviews , living arrangements (living alone and not being married) were reported as barriers to vaccine uptake.
On the macro-level, a lack of confidence (low perceived vaccine effectiveness, higher perceived risk of the vaccine) and complacency issues (lower perceived severity of disease, lower perceived risk of disease) were the most frequently reported 4C components among the elderly.
Studies about pandemic influenza vaccine hesitancy among the elderly were scarce. Complacency (low perceived severity of disease) and a lack of confidence (distrust in authorities) were the only reported barriers to vaccine uptake with regard to the 4C model.
Seasonal vs. pandemic influenza vaccine hesitancy in the general public
For the general public, the uptake of seasonal influenza vaccine was most frequently related to sociodemographic variables (age, gender, education, income, additional risk factors) and past behavior. With regard to the 4C model, a lack of confidence (decreased perceived vaccine effectiveness, increased negative attitude towards vaccines and increased perceived risk of side effects of the vaccine) and complacency issues (decreased worry about the disease, decreased perceived severity of the disease) were most frequently noted as significant barriers to seasonal influenza uptake.
Pandemic influenza vaccine hesitancy was also most frequently related to sociodemographic variables (age, gender, education, additional risk factors) and past behavior. In line with the analysis across all risk groups, the most frequently reported barriers to pandemic influenza vaccine uptake for the general public were complacency (decreased worry about the disease, decreased perceived risk of the disease, decreased severity of the disease and decreased susceptibility to getting the disease) and a lack of confidence (decreased trust in authorities, decreased perceived vaccine effectiveness, decreased perceived subjective norm, increased worry about the safety of the vaccine and increased negative attitude towards the vaccine).
The 4C vaccine hesitancy model
Across risk groups, all reasons against vaccination stated by the 4C model were identified as significant barriers of influenza vaccine hesitancy. However, convenience and calculation played only a minor role. The most frequently reported reasons for pandemic influenza vaccine hesitancy were complacency, especially due to low perceived risk and worry about the disease, and a lack of confidence due to distrust of authorities and decreased perceived safety of the vaccine. For seasonal influenza vaccination, a lack of confidence due to misconceptions and a negative attitude towards the vaccine was the most reported reason for seasonal influenza vaccine hesitancy. For both flu types and across all risk groups, a lack of confidence due to low perceived vaccine effectiveness was frequently reported.
The differences between the two influenza types with regard to their psychological profile of hesitancy as well as the differences between the risk groups described above can illustrate the benefits of applying the 4C model to intervention design. The model provides a heuristic for selecting and designing appropriate strategies to address and overcome vaccine hesitancy . For example, if one aims to increase influenza vaccine uptake within a hospital setting, the results of this review suggest that addressing confidence (by debunking misconceptions and increasing awareness of an ethical and professional obligation to vaccinate) is a promising lever for interventions. Betsch et al. suggest that informational interventions such as educational campaigns are a suitable means by which to address low confidence. It is also shown that structural interventions such as mandatory vaccinations that are suitable to overcome complacency should be treated with care, as negative attitudes towards vaccination are a major barrier and could lead to reactance following structural interventions . Combining the results from this systematic review with conceptual frameworks like the 4C model provides valuable insights about changeable barriers and the potentially effective strategies to overcome them.
The predictive power of psychological variables
The majority of studies report sociodemographic variables as significant determinants of influenza vaccine hesitancy. However, it is important to note that most sociodemographic variables make little contribution to explain influenza vaccine hesitancy on an individual level. Firstly, inconclusive or contradictory findings were obtained especially frequently in the section of sociodemographic variables. Moreover, sociodemographic variables are at best a conglomeration of possible reasons and can never explain a specific behavior without further investigation. For example, a number of studies report an association between the ethnicity of a study population and influenza vaccine uptake [264,495,502,503]). Possible reasons for these findings might be differences in access to care , provider discrimination , negative attitudes towards vaccination , or trust in health authorities  among others . Therefore, variables like ethnicity or gender are carrier variables  of explanatory factors rather than explanatory factors of hesitancy themselves. This means that these variables are potential confounders of variables that actually determine vaccine hesitancy. While such variables may be significantly related to vaccine hesitancy, they cannot be used to explain its emergence or intensity. Most importantly, without looking at psychological factors they are useless to inform interventions to counter hesitancy. While they may have some value in determining the target group of interventions, psychological variables should be used to inform the design of the intervention.
This systematic review describes the landscape of influenza vaccine hesitancy and its determinants rather than their weighted relative importance. Conclusions about the relative importance of determinants cannot be made. When a determinant is reported more frequently than another, then this can mean two things: (1) the variable is a better predictor of vaccine behavior or intention and turned out to be significant in more studies, or (2) the variable was studied more often. Variables like age and gender are the most frequently reported determinants. This probably does not mean that these are the most important variables, but rather that sociodemographic variables are always assessed as part of the research routine and therefore turn out to be significant in some studies. It is important to note that this review does not report and does not take into account studies that assessed the respective barriers and did not obtain significant associations. This was due to the high total number of studies obtained and the scope of the study. For the evaluation of the aggregated effect sizes of potential barriers and their relative importance, a meta-analytic approach is necessary. However, because measured barriers are rarely based on theoretical models and operationalization of constructs varies greatly between studies, meta-analytic approaches face tremendous difficulties addressing influenza vaccine hesitancy.
The majority of studies addressing influenza vaccine hesitancy were conducted in the American and European regions. Studies from all other regions are under-represented. Even though the number of studies for all risk groups has increased over the years, the proportion of studies for children, chronically ill patients and pregnant women remains relatively low. Thus, due to the limited availability of data, the conclusions of this review need to be limited to the regions and populations available. Additionally, the restriction of the search strategy to articles in German or English language may bias search results because it excludes articles from journals in other languages. The inclusion of Global Index Medicus (GIM) libraries may have reduced this bias.
Directions for future research
As a response to the limitations previously discussed, future research needs to address the under-represented regions and populations. This way, designing interventions in all WHO regions and for all risk groups of influenza can base on evidence of influenza vaccine hesitancy.
It is not only important to improve who and which region is studied but also what is studied. Psychological variables provide insights to gain a better understanding of why some individuals refuse to get vaccinated while others do not. Our review may lead to the impression that psychological variables are frequently analyzed. However, the actual measurements are rarely based on psychological theories, and the items used to measure the constructs vary substantially across studies. For example, Loubet et al. measure knowledge by self-evaluation, while Tong et al. developed a 14 item knowledge-scale where the correctness of answers was used to calculate an individual knowledge score . Moreover, especially constructs of risk perception (individual susceptibility, perceived probability, severity and overall judgments of risk) are rarely differentiated and used interchangeably across and even within publications. To ensure valid results and enable the scientific community to compare results between publications, we argue for the use of theory-informed scales of psychological determinants. This will improve the quality of future studies and ensure scientific progress within the research field of influenza vaccine hesitancy. For operationalization of constructs of the TPB and its extensions we provide a collection of items (see S2 Table). We encourage researchers of all disciplines to consider these measurements for future research on influenza vaccine hesitancy.
The first goal of this review was to extract individual barriers to seasonal and pandemic influenza vaccination for risk groups and the general public. On a micro-level we used an extended version of the Theory of Planned Behavior. This review frames the determinants as barriers to vaccine uptake. With regard to the original model of the TPB, a negative attitude towards vaccines and attitudinal beliefs such as a decreased perceived effectiveness of the vaccine and a lack of trust in health authorities were the most frequently reported barriers. Perceiving that influenza vaccination was not the norm in the relevant peer group was frequently reported as a barrier. Relatively few research articles identified low perceived behavioral control as a significant barrier to influenza vaccine uptake. This might be due to the fact that perceived behavioral control is correlated with actual access. Research articles from regions with low reliability of vaccine supply were underrepresented (such as Africa, see Fig 3). This could lead to the overall impression that perceived or actual behavioral control does not play a role. Taking the extensions of the TPB into account, frequently reported additional barriers of influenza vaccine uptake were utility evaluations such as worries about the safety of the vaccine, low perceived severity of the disease and a low perceived risk of the disease. Furthermore, the lacking recommendations from medical personnel, low frequency of interaction with health services and missing vaccination habits were frequently reported as barriers. To frame it differently, the major and most consistent enablers for vaccine uptake on the micro-level were a positive attitude towards influenza vaccines, high perceived utility of vaccination, cues to action, and previous influenza vaccinations.
On a macro-level, the available evidence suggests that confidence, as well as complacency, are major reasons for influenza vaccine hesitancy. Complacency was mostly expressed by low worry, low perceived risk and severity of the disease. The lack of confidence was expressed by doubts about the safety and effectiveness of the vaccine as well as a lack of trust in health authorities and, among other knowledge gaps, the belief that the vaccine can cause the flu.
The second goal was to map knowledge gaps in understanding influenza vaccine hesitancy and to derive directions for further research in this area. We conclude that a more theory-based approach to measuring vaccine hesitancy–not only regarding influenza vaccines–will improve the knowledge base to design effective evidence-informed interventions.
By using evidence-informed approaches to measure and overcome vaccine hesitancy, the effectiveness of vaccine advocacy may be improved and the burden of vaccine-preventable diseases may be reduced.
S1 Table. User query of relevant keywords in Medline via PubMed.
S1 Fig. Identified barriers to influenza vaccine uptake for all risk groups across seasonal and pandemic influenza.
The figure visualizes the total numbers of studies reporting the variable as either decreasing (white) or increasing (black) vaccine acceptance or inconclusive (circled number).
S2 Fig. Identified barriers to seasonal influenza vaccine uptake for HCP.
The figure visualizes the total numbers of studies reporting the variable as either decreasing (white) or increasing (black) vaccine acceptance or inconclusive (circled number).
S3 Fig. Identified barriers to pandemic influenza vaccine uptake for HCP.
The figure visualizes the total numbers of studies reporting the variable as either decreasing (white) or increasing (black) vaccine acceptance or inconclusive (circled number).
S4 Fig. Identified barriers to seasonal influenza vaccine uptake for pregnant women.
S5 Fig. Identified barriers to pandemic influenza vaccine uptake for pregnant women.
S6 Fig. Identified barriers to seasonal influenza vaccine uptake for patients with chronic conditions.
S7 Fig. Identified barriers to pandemic influenza vaccine uptake for patients with chronic conditions.
S8 Fig. Identified barriers to seasonal influenza vaccine uptake for children aged 6 through 59 months.
S9 Fig. Identified barriers to pandemic influenza vaccine uptake for children aged 6 through 59 months.
S10 Fig. Identified barriers to seasonal influenza vaccine uptake for the elderly.
S11 Fig. Identified barriers to pandemic influenza vaccine uptake for the elderly.
S12 Fig. Identified barriers to seasonal influenza vaccine hesitancy for the general public.
S13 Fig. Identified barriers to pandemic influenza vaccine uptake for the general public.
S2 Table. Measurement of constructs of the Theory of Planned Behavior (TPB) and its extensions.
The authors gratefully acknowledge fruitful discussions of previous versions of the manuscript with Claudia Nannei and Erin Grace Sparrow (WHO Headquarters, Geneva).
- Conceptualization: PS CB.
- Formal analysis: PS DR.
- Funding acquisition: CB.
- Investigation: PS DR GL MD.
- Methodology: PS CB.
- Project administration: PS CB.
- Supervision: CB PS.
- Visualization: PS.
- Writing – original draft: PS DR CB.
- Writing – review & editing: PS CB.
- 1. WHO. Seasonal Influenza. Fact Sheet. 2014.
- 2. WHO. The Global Action Plan for Influenza Vaccines Report of the tenth meeting of the Advisory Group of the WHO Global Action Plan for Influenza Vaccines. 2015.
- 3. Poland GA. The 2009–2010 influenza pandemic: effects on pandemic and seasonal vaccine uptake and lessons learned for seasonal vaccination campaigns. Vaccine 2010;28 Suppl 4:D3–13.
- 4. Bish A, Yardley L, Nicoll A, Michie S. Factors associated with uptake of vaccination against pandemic influenza: a systematic review. Vaccine 2011;29:6472–84. pmid:21756960
- 5. Mereckiene J, Cotter S, Nicoll A, Levy-Bruhl D, Ferro A, Tridente G, et al. National seasonal influenza vaccination survey in Europe, 2008. Euro Surveill Bull Eur Sur Les Mal Transm = Eur Commun Dis Bull 2008;13.
- 6. Lin Y, Huang L, Nie S, Liu Z, Yu H, Yan W, et al. Knowledge, attitudes and practices (KAP) related to the pandemic (H1N1) 2009 among Chinese general population: a telephone survey. BMC Infect Dis 2011;11:128. pmid:21575222
- 7. Mak DB, Daly AM, Armstrong PK, Effler P V. Pandemic (H1N1) 2009 influenza vaccination coverage in Western Australia. Med J Aust 2010;193:401–4. pmid:20919971
- 8. CDC. Interim results: state-specific influenza A (H1N1) 2009 monovalent vaccination coverage: United States, October 2009–January 2010. n.d.
- 9. Mereckiene J, Cotter S, Weber JT, Nicoll A, D’Ancona F, Lopalco PL, et al. Influenza A(H1N1)pdm09 vaccination policies and coverage in Europe. Euro Surveill Bull Eur Sur Les Mal Transm = Eur Commun Dis Bull 2012;17.
- 10. Larson HJ, Jarrett C, Eckersberger E, Smith DMD, Paterson P. Understanding vaccine hesitancy around vaccines and vaccination from a global perspective: A systematic review of published literature, 2007–2012. Vaccine 2014;32:2150–9. pmid:24598724
- 11. Jarrett C, Wilson R, O’Leary M, Eckersberger E, Larson HJ, Strategies for addressing vaccine hesitancy—A systematic review. Vaccine 2015;33:4180–90. pmid:25896377
- 12. Strelitz B, Gritton J, Klein EJ, Bradford MC, Follmer K, Zerr DM, et al. Parental vaccine hesitancy and acceptance of seasonal influenza vaccine in the pediatric emergency department. Vaccine 2015;33:1802–7. pmid:25744225
- 13. MacDonald NE, Eskola J, Liang X, Chaudhuri M, Dube E, Gellin B, et al. Vaccine hesitancy: Definition, scope and determinants. Vaccine 2015;33:4161–4. pmid:25896383
- 14. Osterholm MT, Kelley NS, Sommer A, Belongia EA. Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis. Lancet Infect Dis 2012;12:36–44. pmid:22032844
- 15. Osterholm MT, Kelley NS, Manske JM, Ballering KS, Leighton TR, Moore K a. The Compelling Need for Game-Changing Influenza Vaccines An Analysis of the Influenza Vaccine Enterprise and Recommendations for the Future. Cidrap 2012:160.
- 16. CDC. Misconceptions about Seasonal Flu and Flu Vaccines. 2016.
- 17. Yuen CY S, Tarrant M, Determinants of uptake of influenza vaccination among pregnant women—A systematic review. Vaccine 2014;32:4602–13. pmid:24996123
- 18. Nagata JM, Hernández-Ramos I, Kurup AS, Albrecht D, Vivas-Torrealba C, Franco-Paredes C. Social determinants of health and seasonal influenza vaccination in adults ≥65 years: a systematic review of qualitative and quantitative data. BMC Public Health 2013;13:388. pmid:23617788
- 19. Prematunge C, Corace K, McCarthy A, Nair RC, Pugsley R, Garber G. Factors influencing pandemic influenza vaccination of healthcare workers—a systematic review. Vaccine 2012;30:4733–43. pmid:22643216
- 20. Hollmeyer HG, Hayden F, Poland G, Buchholz U. Influenza vaccination of health care workers in hospitals—a review of studies on attitudes and predictors. Vaccine 2009;27:3935–44. pmid:19467744
- 21. Yeung MPS, Lam FLY, Coker R. Factors associated with the uptake of seasonal influenza vaccination in adults: a systematic review. J Public Health (Oxf) 2016.
- 22. Betsch C, Bohm R, Chapman GB. Using Behavioral Insights to Increase Vaccination Policy Effectiveness. Policy Insights from Behav Brain Sci 2015;2:61–73.
- 23. Ajzen I. The theory of planned behavior. Organ Behav Hum Decis Process 1991;50:179–211.
- 24. Rivis A, Sheeran P. Descriptive Norms as an Additional Predictor in the Theory of Planned Behaviour: A Meta-Analysis n.d.
- 25. Schmiege SJ, Bryan A, Klein WMP. Distinctions between worry and perceived risk in the context of the theory of planned behavior. J Appl Soc Psychol 2009;39:95–119.
- 26. Rhodes R, Courneya K. Modelling the theory of planned behaviour and past behaviour. Psychol Health Med 2003;8:57–69. pmid:21888489
- 27. Koo KE, Nurulazam MDA, Rohaida MZS, Teo TG, Salleh Z. Examining the Potential of Safety Knowledge as Extension Construct for Theory of Planned Behaviour: Explaining Safety Practices of Young Adults at Engineering Laboratories and Workshops. Procedia—Soc Behav Sci 2014;116:1513–8.
- 28. Pomery EA, Gibbons FX, Reis-Bergan M, Gerrard M. From willingness to intention: experience moderates the shift from reactive to reasoned behavior. Pers Soc Psychol Bull 2009;35:894–908. pmid:19429884
- 29. Armitage CJ, Conner M. Efficacy of the Theory of Planned Behaviour: a meta-analytic review. Br J Soc Psychol 2001;40:471–99. pmid:11795063
- 30. WHO. Global pandemic influenza action plan to increase vaccine supply. 2006.
- 31. WHO. Global Index Medicus 2015.
- 32. Wilson R J, Paterson P, Jarrett C, Larson HJ, Understanding factors influencing vaccination acceptance during pregnancy globally: A literature review. Vaccine 2015;33:6420–9. pmid:26320417
- 33. Tilburt JC, Mueller PS, Ottenberg AL, Poland GA, Koenig BA. Facing the challenges of influenza in healthcare settings: the ethical rationale for mandatory seasonal influenza vaccination and its implications for future pandemics. Vaccine 2008;26 Suppl 4:D27–30.
- 34. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. Ann Intern Med 2009;151:264. pmid:19622511
- 35. Slovic P, Finucane ML, Peters E, MacGregor DG. Risk as Analysis and Risk as Feelings: Some Thoughts about Affect, Reason, Risk, and Rationality. Risk Anal 2004;24:311–22. pmid:15078302
- 36. Loewenstein GF, Weber EU, Hsee CK, Welch N. Risk as feelings. Psychol Bull 2001;127:267–86. pmid:11316014
- 37. Betsch C, Ulshöfer C, Renkewitz F, Betsch T. The influence of narrative v. statistical information on perceiving vaccination risks. Med Decis Making 2011;31:742–53. pmid:21447730
- 38. Chapman GB, Coups EJ. Emotions and preventive health behavior: worry, regret, and influenza vaccination. Health Psychol 2006;25:82–90. pmid:16448301
- 39. Oria PA, Matini W, Nelligan I, Emukule G, Scherzer M, Oyier B, Morales KF et al. Are Kenyan healthcare workers willing to receive the pandemic influenza vaccine? Results from a cross-sectional survey of healthcare workers in Kenya about knowledge, attitudes and practices concerning infection with and vaccination against 2009 pandemic. Vaccine 2011;29:3617–22. pmid:21296117
- 40. Coulibaly D, Nzussouo NT, Kadjo HA, Traoré Y, Ekra DK, Chérif D, Dagnan SN et al. Pandemic influenza A(H1N1) in cote d’Ivoire: Health-care providers’ knowledge of influenza and attitudes towards vaccination. J Infect Dev Ctries 2013;7:499–506. pmid:23857383
- 41. Betsch C, Wicker S. E-health use, vaccination knowledge and perception of own risk: drivers of vaccination uptake in medical students. Vaccine 2012;30:1143–8. pmid:22192850
- 42. Marentette T, El-Masri MM. Predicting seasonal influenza vaccination among hospital-based nurses. Clin Nurs Res 2011;20:422–38. pmid:21628626
- 43. Rubin GJ, Potts HW, Michie S. Likely uptake of swine and seasonal flu vaccines among healthcare workers. A cross-sectional analysis of UK telephone survey data. Vaccine 2011;29:2421–8. pmid:21277402
- 44. Esteves-Jaramillo A, Omer SB, Gonzalez-Diaz E, Salmon D A, Hixson B, Navarro F, et al. Acceptance of a vaccine against novel Influenza A (H1N1) virus among health Care workers in two major cities in Mexico. Arch Med Res 2009;40:705–11. pmid:20304260
- 45. Mytton OT, O’Moore EM, Sparkes T, Baxi R, Abid M. Knowledge, attitudes and beliefs of health care workers towards influenza vaccination. Occup Med (Lond) 2013;63:189–95.
- 46. Daugherty JD, Blake SC, Grosholz JM, Omer SB, Polivka-West L, Howard DH. Influenza vaccination rates and beliefs about vaccination among nursing home employees. Am J Infect Control 2015;43:100–6. pmid:25637113
- 47. Pareek M, Clark T, Dillon H, Kumar R, Stephenson I. Willingness of healthcare workers to accept voluntary stockpiled H5N1 vaccine in advance of pandemic activity. Vaccine 2009;27:1242–7. pmid:19114078
- 48. Van den Dool C, Van Strien AM, den Akker IL-V, Bonten MJM, Sanders EA, Hak E. Attitude of Dutch hospital personnel towards influenza vaccination. Vaccine 2008;26:1297–302. pmid:18262689
- 49. Zhang J, While AE, Norman IJ. Development and testing of an instrument to assess nurses’ knowledge, risk perception, health beliefs and behaviours related to influenza vaccination. J Clin Nurs 2012;21:2636–46. pmid:22624701
- 50. Zhang J, While AE, Norman IJ. Nurses’ vaccination against pandemic H1N1 influenza and their knowledge and other factors. Vaccine 2012;30:4813–9. pmid:22643215
- 51. Falomir-Pichastor JM, Toscani L, Despointes SH. Determinants of Flu Vaccination among Nurses: The Effects of Group Identification and Professional Responsibility. Appl Psychol An Int Rev 2009;58:42–58.
- 52. Looijmans-Van Den Akker I, Van Delden JJM, Verheij TJ, Van Essen GA, Van der Sande MAB, Hulscher ME, Hak E et al. Which determinants should be targeted to increase influenza vaccination uptake among health care workers in nursing homes? Vaccine 2009;27:4724–30. pmid:19450642
- 53. Al-Tawfiq JA, Antony A, Abed MS. Attitudes towards influenza vaccination of multi-nationality health-care workers in Saudi Arabia. Vaccine 2009;27:5538–41. pmid:19651170
- 54. Arda B, Durusoy R, Yamazhan T, Sipahi OR, Tasbakan M, Pullukcu H, et al. Did the pandemic have an impact on influenza vaccination attitude? A survey among health care workers. BMC Infect Dis 2011;11:87. pmid:21473763
- 55. Hopman CE, Riphagen-Dalhuisen J, Looijmans-van den Akker I, Frijstein G, Van der Geest-Blankert ADJ, Danhof-Pont MB, Gallee PMM et al. Determination of factors required to increase uptake of influenza vaccination among hospital-based healthcare workers. J Hosp Infect 2011;77:327–31. pmid:21316803
- 56. Shrikrishna D, Williams S, Restrick L, Hopkinson NS. Influenza vaccination for NHS staff: Attitudes and uptake. BMJ Open Respir Res 2015;2:1–4.
- 57. Kay MK, Koelemay KG, Kwan-Gett TS, Cadwell BL, Duchin JS. 2009 pandemic influenza a vaccination of pregnant women—King County, Washington State, 2009–2010. Am J Public Health 2012;102 Suppl:S368–74. pmid:22690973
- 58. Keenan H, Campbell J, Evans PH. Influenza vaccination in patients with asthma: why is the uptake so low? Br J Gen Pract 2007;57:359–63. pmid:17504585
- 59. Sintes X, Nebot M, Izquierdo C, Ruiz L, Dominguez A, Bayas JM, et al. Factors associated with pneumococcal and influenza vaccination in hospitalized people aged >/ = 65 years. Epidemiol Infect 2011;139:666–73. pmid:20696084
- 60. Hebert PL, Frick KD, Kane RL, McBean AM. The causes of racial and ethnic differences in influenza vaccination rates among elderly Medicare beneficiaries. Health Serv Res 2005;40:517–37. pmid:15762905
- 61. Villacorta R, Sood N. Determinants of healthcare provider recommendations for influenza vaccinations. Prev Med Reports 2015;2:355–70.
- 62. Li M, Chapman GB, Ibuka Y, Meyers LA, Galvani A. Who got vaccinated against H1N1 pandemic influenza? A longitudinal study in four U.S. cities. Psychol Health 2012;27:101–15. pmid:21736427
- 63. Börjesson M, Enander A. Perceptions and sociodemographic factors influencing vaccination uptake and precautionary behaviours in response to the A/H1N1 influenza in Sweden. Scand J Public Health 2014;42:215–22. pmid:24259541
- 64. Shahrabani S, Benzion U. Workplace vaccination and other factors impacting influenza vaccination decision among employees in Israel. Int J Environ Res Public Health 2010;7:853–69. pmid:20617008
- 65. Porter CK, Fitamaurice G, Tribble DR, Armstrong AW, Mostafa M, Riddle MS. Willingness to receive a hypothetical avian influenza vaccine among US military personnel in mid-deployment. Hum Vaccin Immunother 2013;9:2613–7. pmid:23917256
- 66. Kumar S, Quinn SC, Kim KH, Musa D, Hilyard KM, Freimuth VS. The social ecological model as a framework for determinants of 2009 H1N1 influenza vaccine uptake in the United States. Heal Educ Behav Off Publ Soc Public Heal Educ 2012;39:229–43.
- 67. Naing C, Tan RYP, Soon WC, Parakh J, Sanggi SS. Preventive behaviours towards influenza A(H1N1)pdm09 and factors associated with the intention to take influenza A(H1N1)pdm09 vaccination. J Infect Public Health 2012;5:412–9. pmid:23287612
- 68. Sypsa V, Livanios T, Psichogiou M, Malliori M, Tsiodras S, Nikolakopoulos I, et al. Public perceptions in relation to intention to receive pandemic influenza vaccination in a random population sample: evidence from a cross-sectional telephone survey. Euro Surveill Bull Eur Sur Les Mal Transm = Eur Commun Dis Bull 2009;14.
- 69. Setbon M, Raude J. Factors in vaccination intention against the pandemic influenza A/H1N1. Eur J Public Health 2010;20:490–4. pmid:20444821
- 70. Seale H, Heywood AE, McLaws ML, Ward KF, Lowbridge CP, Van D et al. Why do I need it? I am not at risk! Public perceptions towards the pandemic (H1N1) 2009 vaccine. BMC Infect Dis 2009;10.
- 71. Gidengil CA, Parker AM, Zikmund-Fisher BJ. Trends in risk perceptions and vaccination intentions: a longitudinal study of the first year of the H1N1 pandemic. Am J Public Health 2012;102:672–9. pmid:22397349
- 72. Beattie A, Palmer K, Rees E, Riddell Z, Roberts C, Jordan R. Factors affecting the acceptance of pandemic influenza a H1N1 vaccine amongst essential service providers: A cross sectional study. Vaccines 2013;1:17–33.
- 73. Esteves-Jaramillo A, Omer SB, Gonzalez-Diaz E, Salmon DA, Hixson B, Navarro F, et al. Acceptance of a vaccine against novel influenza A (H1N1) virus among health care workers in two major cities in Mexico. Arch Med Res 2009;40:705–11. pmid:20304260
- 74. Chor JS, Pada SK, Stephenson I, Goggins WB, Tambyah PA, Clarke TW, Law SK et al. Seasonal influenza vaccination predicts pandemic H1N1 vaccination uptake among healthcare workers in three countries. Vaccine 2011;29:7364–9. pmid:21807048
- 75. Bautista D, Vila B, Uso R, Tellez M, Zanon V. Predisposing, reinforcing, and enabling factors influencing influenza vaccination acceptance among healthcare workers. Infect Control Hosp Epidemiol 2006;27:73–77 5p. pmid:16418992
- 76. Ding H, Santibanez TA, Jamieson DJ, Weinbaum CM, Euler GL, Grohskopf LA, et al. Influenza vaccination coverage among pregnant women—National 2009 H1N1 Flu Survey (NHFS). Am J Obstet Gynecol 2011;204:S96–106. pmid:21640233
- 77. Wooten KG, Wortley PM, Singleton JA, Euler GL. Perceptions matter: beliefs about influenza vaccine and vaccination behavior among elderly white, black and Hispanic Americans. Vaccine 2012;30:6927–34. pmid:22939908
- 78. Liao Q, Wong WS, Fielding R. How do anticipated worry and regret predict seasonal influenza vaccination uptake among Chinese adults? Vaccine 2013;31:4084–90. pmid:23867015
- 79. Liao Q, Wong WS, Fielding R. Comparison of Different Risk Perception Measures in Predicting Seasonal Influenza Vaccination among Healthy Chinese Adults in Hong Kong: A Prospective Longitudinal Study. PLoS One 2013;8.
- 80. Sunil TS, Zottarelli LK. Student utilization of a university 2009 H1N1 vaccination clinic. Vaccine 2011;29:4687–9. pmid:21601605
- 81. Maier K, Berkman J, Chatkoff D. Novel virus, atypical risk group: Understanding young adults in college as an under-protected population during H1N1 2009. PLoS Curr 2012:1–12.
- 82. Ha C, Rios LM, Pannaraj PS. Knowledge, attitudes, and practices of school personnel regarding influenza, vaccinations, and school outbreaks. J Sch Health 2013;83:554–61. pmid:23834607
- 83. Ibuka Y, Li M, Vietri J, Chapman GB, Galvani AP. Free-riding behavior in vaccination decisions: an experimental study. PLoS One 2014;9:e87164. pmid:24475246
- 84. Santibanez TA, Mootrey GT, Euler GL, Janssen AP. Behavior and beliefs about influenza vaccine among adults aged 50–64 years. Am J Health Behav 2010;34:77–89. pmid:19663755
- 85. Crowley KA, Myers R, Magda LA, Morse SS, Brandt-Rauf P, Gershon RRM. Prevalence and factors associated with 2009 to 2011 influenza vaccinations at a university medical center. Am J Infect Control 2013;41:824–30. pmid:23485370
- 86. Hothersall EJ, de Bellis-Ayres S, Jordan R. Factors associated with uptake of pandemic influenza vaccine among general practitioners and practice nurses in Shropshire, UK. Prim Care Respir J 2012;21:302–7. pmid:22811218
- 87. Miyakis S, Giannakaki V, Moustakidis E, Trelopoulou A, Trakatelli C, Kotsis V, et al. Vaccination against 2009 pandemic H1N1 influenza among healthcare workers in a tertiary hospital: rates, reasoning, beliefs. J Hosp Infect 2011;78:75–6. pmid:21411186
- 88. Nowrouzi-Kia B, McGeer A. External cues to action and influenza vaccination among post-graduate trainee physicians in Toronto, Canada. Vaccine 2014;32:3830–4. pmid:24837775
- 89. Tuckerman JL, Collins JE, Marshall HS. Factors affecting uptake of recommended immunizations among health care workers in South Australia. Hum Vaccines Immunother 2015;11:704–12.
- 90. Savas E, Tanriverdi D. Knowledge, attitudes and anxiety towards influenza A/H1N1 vaccination of healthcare workers in Turkey. BMC Infect Dis 2010;10:281. pmid:20863386
- 91. Rebmann T, Iqbal A, Anthony J, Knaup RC, Wright KS, Peters EB. H1N1 influenza vaccine compliance among hospital- and non-hospital-based healthcare personnel. Infect Control Hosp Epidemiol 2012;33:737–44. pmid:22669237
- 92. Wiley KE, Massey PD, Cooper SC, Wood NJ, Ho J, Quinn HE, et al. Uptake of influenza vaccine by pregnant women: a cross-sectional survey. Med J Aust 2013;198:373–5. pmid:23581957
- 93. Bodeker B, Walter D, Reiter S, Wichmann O. Cross-sectional study on factors associated with influenza vaccine uptake and pertussis vaccination status among pregnant women in Germany. Vaccine 2014;32:4131–9. pmid:24928791
- 94. Fridman D, Steinberg E, Azhar E, Weedon J, Wilson TE, Minkoff H. Predictors of H1N1 vaccination in pregnancy. Am J Obstet Gynecol 2011;204:S124–7. pmid:21640229
- 95. Cheung KW, Mak YW. Association between psychological flexibility and health beliefs in the uptake of influenza vaccination among people with chronic respiratory diseases in Hong Kong. Int J Environ Res Public Health 2016;13.
- 96. Bodeker B, Remschmidt C, Schmich P, Wichmann O. Why are older adults and individuals with underlying chronic diseases in Germany not vaccinated against flu? A population-based study. BMC Public Health 2015;15:618. pmid:26148480
- 97. Akis S, Velipasaoglu S, Camurdan AD, Beyazova U, Sahn F. Factors associated with parental acceptance and refusal of pandemic influenza A/H1N1 vaccine in Turkey. Eur J Pediatr 2011;170:1165–72. pmid:21347848
- 98. Lau JTF, Mo PKH, Cai YS, Tsui HY, Choi KC. Coverage and parental perceptions of influenza vaccination among parents of children aged 6 to 23 months in Hong Kong. BMC Public Health 2013;13:1026. pmid:24171947
- 99. Matsui D, Shigeta M, Ozasa K, Kuriyama N, Watanabe I, Watanabe Y. Factors associated with influenza vaccination status of residents of a rural community in Japan. BMC Public Health 2011;11:149. pmid:21375758
- 100. Chan T-C, Luk JK-H, Chan FH-W, Chan T-C, Chu L-W, Hung IF-N. Factors associated with seasonal influenza vaccination in Chinese nursing home older adults. J Am Med Dir Assoc 2013;14:772–4. pmid:23916374
- 101. Anne-Laure CB, Jocelyn R, Nathanaël L, De-Lambal X, Fabrice C, Michel S. Predictors of IV behaviors during and after the 2009 influenza pandemic in France. Vaccine 2014;32:2007–15. pmid:24434043
- 102. Lau JTF, Kim JH, Tsui HY, Griffiths S. Perceptions related to bird-to-human avian influenza, influenza vaccination, and use of face mask. Infection 2008;36:434–43. pmid:18795229
- 103. Caballero P, Tuells J, Duro-Torrijos JL, Nolasco A. Acceptability of pandemic A(H1N1) influenza vaccination by Essential Community Workers in 2010 Alicante (Spain), perceived seriousness and sources of information. Prev Med (Baltim) 2013;57:725–8.
- 104. Kiviniemi MT, Ram PK, Kozlowski LT, Smith KM. Perceptions of and willingness to engage in public health precautions to prevent 2009 H1N1 influenza transmission. BMC Public Health 2011;11:152. pmid:21385436
- 105. Huang J-H, Miao Y-Y, Kuo P-C. Pandemic influenza H1N1 vaccination intention: psychosocial determinants and implications from a national survey, Taiwan. Eur J Public Health 2012;22:796–801. pmid:22102631
- 106. Eastwood K, Durrheim DN, Jones A, Butler M. Acceptance of pandemic (H1N1) 2009 influenza vaccination by the Australian public. Med J Aust 2010;192:33–6. pmid:20047546
- 107. Chuang Y-C, Huang Y-L, Tseng K-C, Yen C-H, Yang L. Social capital and health-protective behavior intentions in an influenza pandemic. PLoS One 2015;10:e0122970. pmid:25874625
- 108. Chen N-TN, Murphy ST. Examining the role of media coverage and trust in public health agencies in H1N1 influenza prevention. In: Merrick J, Merrick J (Ed), editors. Public Heal. Yearb. 2011., Chen, Nien-Tsu Nancy, Annenberg School for Communication and Journalism, University of Southem California, 3502 Watt Way, Los Angeles, CA, US, 90089–0281: Nova Biomedical Books; 2013, p. 41–50.
- 109. Lau JT, Au DW, Tsui HY, Choi KC. Prevalence and determinants of influenza vaccination in the Hong Kong Chinese adult population. Am J Infect Control 2012;40:e225–7. pmid:22743046
- 110. Hou Z, Chang J, Yue D, Fang H, Meng Q, Zhang Y. Determinants of willingness to pay for self-paid vaccines in China. Vaccine 2014;32:4471–7. pmid:24968160
- 111. Gargano LM, Painter JE, Sales JM, Morfaw C, Jones LM, Murray D, et al. Seasonal and 2009 H1N1 influenza vaccine uptake, predictors of vaccination, and self-reported barriers to vaccination among secondary school teachers and staff. Hum Vaccin 2011;7:89–95. pmid:21263225
- 112. Rebmann T, Wright KS, Anthony J, Knaup RC, Peters EB. Seasonal influenza vaccine compliance among hospital-based and nonhospital-based healthcare workers. Infect Control Hosp Epidemiol 2012;33:243–9. pmid:22314061
- 113. Lehmann BA, Ruiter RAC, van Dam D, Wicker S, Kok G. Sociocognitive predictors of the intention of healthcare workers to receive the influenza vaccine in Belgian, Dutch and German hospital settings. J Hosp Infect 2015;89:202–9. pmid:25586987
- 114. Loulergue P, Moulin F, Vidal-Trecan G, Absi Z, Demontpion C, Menager C, Launay O et al. Knowledge, attitudes and vaccination coverage of healthcare workers regarding occupational vaccinations. Vaccine 2009;27:4240–3. pmid:19481314
- 115. Yuet Sheung Yuen C, Yee Tak Fong D, Lai Yin Lee I, Chu S, Sau-mei Siu E, Tarrant M. Prevalence and predictors of maternal seasonal influenza vaccination in Hong Kong. Vaccine 2013;31:5281–8. pmid:24016814
- 116. Frew PM, Saint-Victor DS, Owens LE, Omer SB. Socioecological and message framing factors influencing maternal influenza immunization among minority women. Vaccine 2014;32:1736–44. pmid:24486366
- 117. Henninger M, Naleway A, Crane B, Donahue J, Irving S. Predictors of seasonal influenza vaccination during pregnancy. Obstet Gynecol 2013;121:741–9. pmid:23635673
- 118. Kouassi DP, Coulibaly D, Foster L, Kadjo H, N’Zussuouo T, Traore Y, et al. Vulnerable groups within a vulnerable population: awareness of the A(H1N1)pdm09 pandemic and willingness to be vaccinated among pregnant women in Ivory Coast. J Infect Dis 2012;206 Suppl:S114–20. pmid:23169956
- 119. Chen M-F, Wang R-H, Schneider JK, Tsai C-T, Jiang DD-S, Hung M-N, et al. Using the Health Belief Model to understand caregiver factors influencing childhood influenza vaccinations. J Community Health Nurs 2011;28:29–40. pmid:21279888
- 120. van der Weerd W, Timmermans DR, Beaujean DJ, Oudhoff J, van Steenbergen JE. Monitoring the level of government trust, risk perception and intention of the general public to adopt protective measures during the influenza A (H1N1) pandemic in The Netherlands. BMC Public Health 2011;11:575. pmid:21771296
- 121. Keller JJ, Kim JH, Lau JCH, Wong AH, Griffiths SM. Intention to engage in preventive behaviors in response to the A/H1N1 pandemic among university entrants in four Chinese cities. Asia Pac J Public Health 2014;26:42–7. pmid:24097917
- 122. Rudisill C. How do we handle new health risks? Risk perception, optimism, and behaviors regarding the H1N1 virus. J Risk Res 2013;16:959–80.
- 123. Yi S, Nonaka D, Nomoto M, Kobayashi J, Mizoue T. Predictors of the uptake of A (H1N1) influenza vaccine: findings from a population-based longitudinal study in Tokyo. PLoS One 2011;6:e18893. pmid:21556152
- 124. Agarwal V. A/H1N1 Vaccine Intentions in College Students: An Application of the Theory of Planned Behavior. J Am Coll Heal 2014;62:416–24.
- 125. Mok E, Yeung SH, Chan MF. Prevalence of influenza vaccination and correlates of intention to be vaccinated among Hong Kong Chinese. Public Health Nurs 2006;23:506–15. pmid:17096775
- 126. Tsai YY, Lee JJ,Hsieh WH. Determinants of the public intent to receive the seasonal influenza vaccine and protective behaviors: A population-based study in Taiwan. Vaccine 2014;32:6667–75. pmid:25240751
- 127. Malosh R, Ohmit SE, Petrie JG, Thompson MG, Aiello AE, Monto AS. Factors associated with influenza vaccine receipt in community dwelling adults and their children. Vaccine 2014;32:1841–7. pmid:24530926
- 128. Frew PM, Hixson B, del Rio C, Esteves-Jaramillo A, Omer SB. Acceptance of pandemic 2009 influenza A (H1N1) vaccine in a minority population: determinants and potential points of intervention. Pediatrics 2011;127 Suppl:S113–9. pmid:21502254
- 129. Shroufi A, Copping J, Musonda P, Vivancos R, Langden V, Armstrong S et al. Influenza vaccine uptake among staff in care homes in Nottinghamshire: A random cluster sample survey. Public Health 2009;123:645–9. pmid:19875140
- 130. lbano L, Matuozzo A, Marinelli P, Di Giuseppe G. Knowledge, attitudes and behaviour of hospital health-care workers regarding influenza A/H1N1: A cross sectional survey. BMC Infect Dis 2014;14.
- 131. Crowley KA, Myers R, Magda LA, Morse SS, Brandt-Rauf P, Gershon RR. Prevalence and factors associated with 2009 to 2011 influenza vaccinations at a university medical center. Am J Infect Control 2013;41:824–30. pmid:23485370
- 132. Torun SD, Torun F. Vaccination against pandemic influenza A/H1N1 among healthcare workers and reasons for refusing vaccination in Istanbul in last pandemic alert phase. Vaccine 2010;28:5703–10. pmid:20600497
- 133. Kaboli F, Astrakianakis G, Li G, Guzman J, Naus M, Donovan T. Influenza vaccination and intention to receive the pandemic H1N1 influenza vaccine among healthcare workers of British Columbia, Canada: a cross-sectional study [corrected] [published erratum appears in INFECT CONTROL HOSP EPIDEMIOL 2010 Dec;31(12):1316]. Infect Control Hosp Epidemiol 2010;31:1017–1024 8p. pmid:20707670
- 134. Gorman JR, Brewer NT, Wang JB, Chambers CD. Theory-based predictors of influenza vaccination among pregnant women. Vaccine 2012;31:213–8. pmid:23123019
- 135. Tucker Edmonds BM, Coleman J, Armstrong K, Shea JA, Edmonds BMT, Coleman J, et al. Risk perceptions, worry, or distrust: What drives pregnant women’s decisions to accept the H1N1 vaccine? Matern Child Health J 2011;15:1203–9. pmid:20936337
- 136. Kwong EWY, Lam IOY, Chan TMF. What factors affect influenza vaccine uptake among community-dwelling older Chinese people in Hong Kong general outpatient clinics? [corrected] [published erratum appears in J CLIN NURS 2009 Jun;18(12):1816]. J Clin Nurs 2009;18:960–971 12p. pmid:19207795
- 137. SteelFisher GK, Blendon RJ, Kang M, Ward JRM, Kahn EB, Maddox KEW, et al. Adoption of preventive behaviors in response to the 2009 H1N1 influenza pandemic: A multiethnic perspective. Influenza Other Respi Viruses 2015;9:131–42.
- 138. Renner B, Reuter T. Predicting vaccination using numerical and affective risk perceptions: The case of A/H1N1 influenza. Vaccine 2012;30:7019–26. pmid:23046542
- 139. Peng Y, Xu Y, Zhu M, Yu H, Nie S, Yan W. Chinese urban-rural disparity in pandemic (H1N1) 2009 vaccination coverage rate and associated determinants: a cross-sectional telephone survey. Public Health 2013;127:930–7. pmid:24139202
- 140. Ludolph R, Nobile M, Hartung U, Castaldi S, Schulz P. H1N1 influenza pandemic in Italy revisited: Has the willingness to get vaccinated suffered in the long run? J Public Health Res 2015;4:142–7.
- 141. Prati G, Pietrantoni L, Zani B. Compliance with recommendations for pandemic influenza H1N1 2009: the role of trust and personal beliefs. Health Educ Res 2011;26:761–9. pmid:21613380
- 142. Rönnerstrand B. Social capital and immunisation against the 2009 A(H1N1) pandemic in Sweden. Scand J Public Health 2013;41:853–9. pmid:23843025
- 143. Painter JE, Gargano LM, Sales JM, Morfaw C, Jones LM, Murray D, et al. Correlates of 2009 H1N1 influenza vaccine acceptability among parents and their adolescent children. Health Educ Res 2011;26:751–60. pmid:21536717
- 144. Kwon Y, Cho H-Y, Lee Y-K, Bae G-R, Lee S-G. Relationship between intention of novel influenza A (H1N1) vaccination and vaccination coverage rate. Vaccine 2010;29:161–5. pmid:21055495
- 145. Horney JA, Moore Z, Davis M, MacDonald PDM. Intent to receive pandemic influenza A (H1N1) vaccine, compliance with social distancing and sources of information in NC, 2009. PLoS One 2010;5:e11226. pmid:20585462
- 146. Gargano LM, Painter JE, Sales JM, Morfaw C, Jones LM, Weiss P, et al. Correlates of 2009 pandemic H1N1 influenza vaccine acceptance among middle and high school teachers in rural Georgia. J Sch Health 2011;81:297–303. pmid:21592124
- 147. Mesch GS, Schwirian KP. Social and political determinants of vaccine hesitancy: Lessons learned from the H1N1 pandemic of 2009–2010. Am J Infect Control 2015;43:1161–5. pmid:26521933
- 148. Ferrante G, Baldissera S, Moghadam PF, Carrozzi G, Trinito MO, Salmaso S. Surveillance of perceptions, knowledge, attitudes and behaviors of the Italian adult population (18–69 years) during the 2009–2010 A/H1N1 influenza pandemic. Eur J Epidemiol 2011;26:211–9. pmid:21476080
- 149. Chen JY, Fox SA, Cantrel CH, Stockdale SE. Health disparities and prevention: Racial/ethnic barriers to flu vaccinations. J Community Health 2007;32:5–20. pmid:17269310
- 150. Tsutsui Y, Benzion U, Shahrabani S. Economic and behavioral factors in an individual’s decision to take the influenza vaccination in Japan. J Socio Econ 2012;41:594–602.
- 151. Merrill RM, Kelley TA, Cox E, Layman AB, Layton BJ, Lindsay R. Factors and barriers influencing influenza vaccination among students at Brigham Young University. Med Sci Monit 2010;16:PH29–34. pmid:20110927
- 152. Chan T-C, Fu Y, Wang D-W, Chuang J-H. Determinants of receiving the pandemic (H1N1) 2009 vaccine and intention to receive the seasonal influenza vaccine in Taiwan. PLoS One 2014;9:e101083. pmid:24971941
- 153. Godin G, Vezina-Im L, Naccache H. Determinants of influenza vaccination among healthcare workers. Infect Control Hosp Epidemiol 2010;31:689–93. pmid:20482373
- 154. Liao Q, Cowling BJ, Lam WWT, Fielding R. Factors affecting intention to receive and self-reported receipt of 2009 pandemic (H1N1) vaccine in Hong Kong: A longitudinal study. PLoS One 2011;6.
- 155. Myers LB, Goodwin R. Determinants of adults’ intention to vaccinate against pandemic swine flu. BMC Public Health 2011;11:15. pmid:21211000
- 156. Leder S, Florack A, Keller J. Self-regulation and protective health behaviour: how regulatory focus and anticipated regret are related to vaccination decisions. Psychol Health 2015;30:165–88. pmid:25137215
- 157. Gallagher S, Povey R. Determinants of older adults’ intentions to vaccinate against influenza: a theoretical application. J Public Health (Oxf) 2006;28:139–44.
- 158. Kraut A, Graff L, McLean D. Behavioral change with influenza vaccination: Factors influencing increased uptake of the pandemic H1N1 versus seasonal influenza vaccine in health care personnel. Vaccine 2011;29:8357–63. pmid:21888939
- 159. Rebmann T, Iqbal A, Anthony J, Knaup RC, Wright KS, Peters EB. H1N1 influenza vaccine compliance among hospital- and non-hospital-based healthcare personnel. Infect Control Hosp Epidemiol 2012;33:737–44. pmid:22669237
- 160. Rebmann T, Wright KS, Anthony J, Knaup RC, Peters EB. Seasonal and H1N1 influenza vaccine compliance and intent to be vaccinated among emergency medical services personnel. Am J Infect Control 2012;40:632–6. pmid:22464038
- 161. Hauri AM, Uphoff H, Gussmann V, Gawrich S. Factors that affect influenza vaccine uptake among staff of long-term care facilities. Infect Control Hosp Epidemiol 2006;27:638–41. pmid:16755489
- 162. Hellyer JMH, DeVries AS, Jenkins SM, Lackore KA, James KM, Ziegenfuss JY, et al. Attitudes toward and Uptake of H1N1 Vaccine among Health Care Workers during the 2009 H1N1 Pandemic. PLoS One 2011;6.
- 163. Hothersall EJ, de Bellis-Ayres S, Jordan R. Factors associated with uptake of pandemic influenza vaccine among general practitioners and practice nurses in Shropshire, UK. Prim Care Respir J 2012;21:302–7. pmid:22811218
- 164. Lau JT, Cai Y, Tsui HY, Choi KC. Prevalence of influenza vaccination and associated factors among pregnant women in Hong Kong. Vaccine 2010;28:5389–97. pmid:20542072
- 165. Bödeker B, Walter D, Reiter S, Wichmann O. Cross-sectional study on factors associated with influenza vaccine uptake and pertussis vaccination status among pregnant women in Germany. Vaccine 2014;32:4131–9. pmid:24928791
- 166. Henninger M, Naleway A, Crane B, Donahue J, Irving S. Predictors of seasonal influenza vaccination during pregnancy. Obstet Gynecol 2013;121:741–9. pmid:23635673
- 167. Dlugacz Y, Fleischer A, Carney MT, Copperman N, Ahmed I, Ross Z, et al. 2009 H1N1 vaccination by pregnant women during the 2009–10 H1N1 influenza pandemic. Am J Obstet Gynecol 2012;206:339.e1–8.
- 168. Lau JT, Yang X, Tsui HY, Kim JH. Prevalence of influenza vaccination and associated factors among community-dwelling Hong Kong residents of age 65 or above. Vaccine 2006;24:5526–34. pmid:16716461
- 169. Kravos A, Kracun L, Kravos K, Iljaz R. The Impact of Patient’s Socio-Demographic Characterictics, Comorbidities and Attitudes on Flu Vaccination Uptake in Family Practice Settings. Zdr Varst 2015;54:204–11. pmid:27646728
- 170. Offutt-Powell TN, Ojha RP, Qualls-Hampton R, Stonecipher S, Singh KP, Cardarelli KM. Parental risk perception and influenza vaccination of children in daycare centres. Epidemiol Infect 2014;142:134–41. pmid:23594431
- 171. Shono A, Kondo M. Parents’ preferences for seasonal influenza vaccine for their children in Japan. Vaccine 2014;32:5071–6. pmid:25063570
- 172. Podlesek A, Roskar S, Komidar L. Some factors affecting the decision on non-mandatory vaccination in an influenza pandemic: comparison of pandemic (H1N1) and seasonal influenza vaccination. Zdr Varst 2011;50:227–38.
- 173. Redelings MD, Piron J, Smith L V, Chan A, Heinzerling J, Sanchez KM, et al. Knowledge, attitudes, and beliefs about seasonal influenza and H1N1 vaccinations in a low-income, public health clinic population. Vaccine 2012;30:454–8. pmid:22044740
- 174. Torun SD, Torun F, Catak B. Healthcare workers as parents: attitudes toward vaccinating their children against pandemic influenza A/H1N1. BMC Public Health 2010;10:596. pmid:20932342
- 175. Corace K, Prematunge C, McCarthy A, Nair RC, Roth V, Hayes T, Garbe G et al. Predicting influenza vaccination uptake among health care workers: What are the key motivators? Am J Infect Control 2013;41:679–84. pmid:23523520
- 176. Thompson MG, Gaglani MJ, Naleway A, Ball S, Henkle EM, Sokolow LZ, Kennedy ED et al. The expected emotional benefits of influenza vaccination strongly affect pre-season intentions and subsequent vaccination among healthcare personnel. Vaccine 2012;30:3557–65. pmid:22475860
- 177. Taksdal SE, Mak DB, Joyce S, Tomlin S, Carcione D, Armstrong PK, et al. Predictors of uptake of influenza vaccination—a survey of pregnant women in Western Australia. Aust Fam Physician 2013;42:582–6. pmid:23971070
- 178. Gorman JR, Chambers CD. Pregnant women’s attitudes toward influenza vaccination while breastfeeding. Prev Med Reports 2015;2:333–6.
- 179. Tsuchiya Y, Shida N, Machida K. Flu vaccination acceptance among children and awareness of mothers in Japan. Procedia Vaccinol 2014;8:12–7.
- 180. Chow MYK, King C, Leask J. Parents intentions and behavior regarding seasonal influenza vaccination for their children: A survey in child-care centers in Sydney, Australia. J Pediatr Infect Dis 2012;7:89–96.
- 181. Wu CST, Kwong EWY, Wong HT, Lo SH, Wong ASW. Beliefs and knowledge about vaccination against AH1N1pdm09 infection and uptake factors among Chinese parents. Int J Environ Res Public Health 2014;11:1989–2002. pmid:24534766
- 182. Galarce EM, Minsky S, Viswanath K. Socioeconomic status, demographics, beliefs and A(H1N1) vaccine uptake in the United States. Vaccine 2011;29:5284–9. pmid:21621577
- 183. Wiese-Posselt M, Leitmeyer K, Hamouda O, Bocter N, Zöllner I, Haas W et al. Influenza vaccination coverage in adults belonging to defined target groups, Germany, 2003/2004. Vaccine 2006;24:2560–6. pmid:16414160
- 184. Newcombe J, Kaur R, Wood N, Seale H, Palasanthiran P, Snelling T. Prevalence and determinants of influenza vaccine coverage at tertiary pediatric hospitals. Vaccine 2014;32:6364–8. pmid:24962754
- 185. Suryadevara M, Bonville CA, Rosenbaum PF, Domachowske JB. Influenza vaccine hesitancy in a low-income community in central New York State. Hum Vaccines Immunother 2014;10:2098–103.
- 186. van Delden JJM, Ashcroft R, Dawson A, Marckmann G, Upshur R, Verweij MF. The ethics of mandatory vaccination against influenza for health care workers. Vaccine 2008;26:5562–6. pmid:18722495
- 187. Mak KK, Yiu YF, Ko KL, Hui KSH, Mak KM, Mak LY, et al. Attitudes and perceptions of influenza vaccination among Hong Kong doctors and medical students before the 2009 pandemic. Eur J Public Health 2012;23.
- 188. Shim E, Chapman GB, Townsend JP, Galvani AP. The influence of altruism on influenza vaccination decisions. J R Soc Interface 2012;9:2234–43. pmid:22496100
- 189. Janks M, Cooke S, Odedra A, Kang H, Bellman M, Jordan RE. Factors affecting acceptance and intention to receive pandemic influenza a H1N1 vaccine among primary school children: A cross-sectional study in Birmingham, UK. Influenza Res Treat 2012;2012.
- 190. Rehmani R, Memon JI. Knowledge, attitudes and beliefs regarding influenza vaccination among healthcare workers in a Saudi hospital. Vaccine 2010;28:4283–7. pmid:20441803
- 191. Quinn SC, Kumar S, Freimuth VS, Kidwell K, Musa D. Public willingness to take a vaccine or drug under Emergency Use Authorization during the 2009 H1N1 pandemic. Biosecur Bioterror 2009;7:275–90. pmid:19775200
- 192. Quach S, Hamid JS, Pereira JA, Heidebrecht CL, Deeks SL, Crowcroft NS, Kwong JC, et al. Influenza vaccination coverage across ethnic groups in Canada. CMAJ 2012;184:1673–81. pmid:22966054
- 193. Schwarzinger M, Verger P, Guerville M-A, Aubry C, Rolland S, Obadia Y, et al. Positive attitudes of French general practitioners towards A/H1N1 influenza-pandemic vaccination: a missed opportunity to increase vaccination uptakes in the general public? Vaccine 2010;28:2743–8. pmid:20117271
- 194. Looijmans-van den Akker I, van Delden JJM, Verheij TJM, van Essen GA, van der Sande MAB, Hulscher ME, et al. Which determinants should be targeted to increase influenza vaccination uptake among health care workers in nursing homes? Vaccine 2009;27:4724–30. pmid:19450642
- 195. Frew PM, Owens L, Saint-Victor DS, Benedict S, Zhang S, Omer SB. Factors associated with maternal influenza immunization decision-making. Evidence of immunization history and message framing effects. Hum Vaccin Immunother 2014;10:2576–83. pmid:25483468
- 196. Lin CJ, Nowalk MP, Zimmerman RK, Ko F-S, Zoffel L, Hoberman A, et al. Beliefs and attitudes about influenza immunization among parents of children with chronic medical conditions over a two-year period. J Urban Health 2006;83:874–83. pmid:16770701
- 197. Kiberd MB, Cooper C, Slaunwhite JM, Halperin B, Haase D, McNeil SA. Pandemic influenza is a strong motivator for participation in vaccine clinical trials among HIV-positive Canadian adults. Can J Infect Dis Med Microbiol 2009;20:e124–9. pmid:21119788
- 198. Frew PM, Painter JE, Hixson B, Kulb C, Moore K, del Rio C, et al. Factors mediating seasonal and influenza A (H1N1) vaccine acceptance among ethnically diverse populations in the urban south. Vaccine 2012;30:4200–8. pmid:22537991
- 199. de Perio MA, Wiegand DM, Evans SM, Perio MA, Wiegand DM, Evans SM. Low Influenza Vaccination Rates Among Child Care Workers in the United States: Assessing Knowledge, Attitudes, and Behaviors. J Community Health 2012;37:272–81. pmid:21938550
- 200. Wang W, Ahern L. Acting on surprise: emotional response, multiple-channel information seeking and vaccination in the H1N1 flu epidemic. Soc Influ 2015;10:137–48.
- 201. Nyhan B, Reifler J, Richey S. The role of social networks in influenza vaccine attitudes and intentions among college students in the Southeastern United States. J Adolesc Health 2012;51:302–4. pmid:22921143
- 202. Cornally N, Ann Deasy E, McCarthey G, McAuley C, Moran J, Weathers E, et al. Student nurses’ intention to get the influenza vaccine. Br J Nurs 2013;22:1207–11. pmid:24280920
- 203. Takayanagi IJ, Cardoso MRA, Costa SF, Araya MES, Machado CM. Attitudes of health care workers to influenza vaccination: Why are they not vaccinated? Am J Infect Control 2007;35:56–61. pmid:17276792
- 204. Lehmann BA, Ruiter RA, Chapman G, Kok G. The intention to get vaccinated against influenza and actual vaccination uptake of Dutch healthcare personnel. Vaccine 2014;32:6986–91. pmid:25454867
- 205. Daley MF, Crane LA, Chandramouli V, Beaty BL, Barrow J, Allred N, et al. Misperceptions about influenza vaccination among parents of healthy young children. Clin Pediatr (Phila) 2007;46:408–17.
- 206. Frew PM, Saint-Victor DS, Owens LE, Omer SB. Socioecological and message framing factors influencing maternal influenza immunization among minority women. Vaccine 2014;32:1736–44. pmid:24486366
- 207. de Perio MA, Wiegand DM, Evans SM. Low influenza vaccination rates among child care workers in the United States: assessing knowledge, attitudes, and behaviors. J Community Health 2012;37:272–81. pmid:21938550
- 208. Perio MA de, Wiegand DM, Brueck SE. Influenza vaccination coverage among school employees: assessing knowledge, attitudes, and behaviors. J Sch Health 2014;84.
- 209. Liao Q, Cowling BJ, Lam WWT, Fielding R. Factors affecting intention to receive and self-reported receipt of 2009 pandemic (H1N1) vaccine in Hong Kong: a longitudinal study. PLoS One 2011;6:e17713. pmid:21412418
- 210. Gargano LM, Painter JE, Sales JM, Morfaw C, Jones LM, Murray D, Hughes JM, et al. Seasonal and 2009 H1N1 influenza vaccine uptake, predictors of vaccination and self-reported barriers to vaccination among secondary school teachers and staff. Hum Vaccin 2011;7:89–95. pmid:21263225
- 211. Hopman CE, Riphagen-Dalhuisen J, Looijmans-van den Akker I, Frijstein G, Van der Geest-Blankert ADJ, Danhof-Pont MB, et al. Determination of factors required to increase uptake of influenza vaccination among hospital-based healthcare workers. J Hosp Infect 2011;77:327–31. pmid:21316803
- 212. Hellyer JMH, DeVries AS, Jenkins SM, Lackore KA, James KM, Ziegenfuss JY, Tilburt JC, et al. Attitudes toward and uptake of H1N1 vaccine among health care workers during the 2009 H1N1 pandemic. PLoS One 2011;6.
- 213. Godin G, Vezina-Im L-A, Naccache H. Determinants of influenza vaccination among healthcare workers. Infect Control Hosp Epidemiol 2010;31:689–93. pmid:20482373
- 214. Torun SD, Torun F. Vaccination against pandemic influenza A/H1N1 among healthcare workers and reasons for refusing vaccination in Istanbul in last pandemic alert phase. Vaccine 2010;28:5703–10. pmid:20600497
- 215. Cowan AE, Winston CA, Davis MM, Wortley PM, Clark SJ, et al. Influenza vaccination status and influenza-related perspectives and practices among US physicians. Am J Infect Control 2006;34:164–9. pmid:16679171
- 216. Mallari J, Goad J, Wu J, Johnson K, Forman T, Neinstein L. Knowledge, attitudes, and practices regarding influenza vaccination among health professional students. J Am Pharm Assoc (2003) 2007;47:498–502.
- 217. Mak KK, Yiu YF, Ko KL, Hui KSH, Mak KM, Mak LY, et al. Attitudes and perceptions of influenza vaccination among Hong Kong doctors and medical students before the 2009 pandemic. Eur J Public Health 2013;23:257–62. pmid:22383477
- 218. Henriksen Hellyer JM, DeVries AS, Jenkins SM, Lackore KA, James KM, Ziegenfuss JY, et al. Attitudes toward and uptake of H1N1 vaccine among health care workers during the 2009 H1N1 pandemic. PLoS One 2011;6:e29478. pmid:22216290
- 219. Lau JTF, Yeung NCY, Choi KC, Cheng MYM, Tsui HY, Griffiths S. Factors in association with acceptability of A/H1N1 vaccination during the influenza A/H1N1 pandemic phase in the Hong Kong general population. Vaccine 2010;28:4632–7. pmid:20457289
- 220. de Perio MA, Wiegand DM, Brueck SE. Influenza vaccination coverage among school employees: assessing knowledge, attitudes, and behaviors. J Sch Health 2014;84:586–92. pmid:25117893
- 221. Myers LB, Goodwin R. Using a theoretical framework to determine adults’ intention to vaccinate against pandemic swine flu in priority groups in the UK. Public Health 2012;126:S53–6. pmid:22784583
- 222. Lau L, Lau YH, Lau YH. Prevalence and correlates of influenza vaccination among non-institutionalized elderly people: an exploratory cross-sectional survey. Int J Nurs Stud 2009;46:768–77. pmid:19162264
- 223. Chen C-H, Chiu P-J, Chih Y-C, Yeh G-L. Determinants of influenza vaccination among young Taiwanese children. Vaccine 2015;33:1993–8. pmid:25613722
- 224. Cole AP, Gill JM, Fletcher KD, Shivers CA, Allen LC, Mwendwa DT. Understanding African American College Students’ H1N1 Vaccination Decisions. Heal Psychol 2015;34:1185–90.
- 225. Hilyard KM, Quinn SC, Kim KH, Musa D, Freimuth VS. Determinants of Parental Acceptance of the H1N1 Vaccine. Heal Educ Behav 2014;41:307–14.
- 226. Hilyard KM, Quinn SC, Kim KH, Musa D, Freimuth VS. Determinants of parental acceptance of the H1N1 vaccine. Heal Educ Behav 2014;41:307–14.
- 227. Lehmann BA, Ruiter RAC, Van Dam D, Wicker S, Kok G. Sociocognitive predictors of the intention of healthcare workers to receive the influenza vaccine in Belgian, Dutch and German hospital settings. J Hosp Infect 2015;89:202–9. pmid:25586987
- 228. Lehmann BA, Ruiter RAC, Wicker S, Chapman G, Kok G. Medical students’ attitude towards influenza vaccination. BMC Infect Dis 2015;15:185. pmid:25884906
- 229. Baron-Epel O, Madjar B, Grefat R, Rishpon S. Trust and the demand for autonomy may explain the low rates of immunizations among nurses. Hum Vaccines Immunother 2013;9:100–7.
- 230. Norton SP, Scheifele DW, Bettinger JA, West RM. Influenza vaccination in paediatric nurses: Cross-sectional study of coverage, refusal, and factors in acceptance. Vaccine 2008;26:2942–8. pmid:18448210
- 231. Rebmann T, Wright KS, Anthony J, Knaup RC, Peters EB. Seasonal influenza vaccine compliance among hospital-based and nonhospital-based healthcare workers. Infect Control Hosp Epidemiol 2012;33:243–9. pmid:22314061
- 232. Henninger ML, Irving SA, Thompson M, Avalos LA, Ball SW, Shifflett P et al. Factors associated with seasonal influenza vaccination in pregnant women. J Women’s Heal 2015;24:394–402.
- 233. Tong A, Biringer A, Ofner-Agostini M, Upshur R, McGeer A. A cross-sectional study of maternity care providers’ and women’s knowledge, attitudes, and behaviours towards influenza vaccination during pregnancy. J Obstet Gynaecol Can 2008;30:404–10. pmid:18505664
- 234. Henninger ML, Irving SA, Thompson M, Avalos LA, Ball SW, Shifflett P, et al. Factors associated with seasonal influenza vaccination in pregnant women. J Women’s Heal 2015;24:394–402.
- 235. Lau JTF, Cai Y, Tsui HY, Choi KC. Prevalence of influenza vaccination and associated factors among pregnant women in Hong Kong. Vaccine 2010;28:5389–97. pmid:20542072
- 236. Tarrant M, Wu KM, Yuen CYS, Cheung KL, Chan VHS. Determinants of 2009 A/H1N1 influenza vaccination among pregnant women in Hong Kong. Matern Child Health J 2013;17:23–32. pmid:22297574
- 237. Turner S, de Souza RJ, Kumareswaran R, Singh SM. Barriers to Influenza Vaccination in Patients with Implantable Cardiac Defibrillators. Can J Cardiovasc Nurs 2015;25:17–23. pmid:26387272
- 238. Loubet P, Kernéis S, Groh M, Loulergue P, Blanche P, Verger P et al. Attitude, knowledge and factors associated with influenza and pneumococcal vaccine uptake in a large cohort of patients with secondary immune deficiency. Vaccine 2015;33:3703–8. pmid:26073016
- 239. Gnanasekaran SK, Finkelstein JA, Hohman K, O’Brien M, Kruskal B, Lieu T, et al. Parental perspectives on influenza vaccination among children with asthma. Public Health Rep 2006;121:181–188 8p. pmid:16528952
- 240. Chanel O, Luchini S, Massoni S, Vergnaud JC. Impact of information on intentions to vaccinate in a potential epidemic: Swine-origin Influenza A (H1N1). Soc Sci Med 2011;72:142–8. pmid:21163566
- 241. Rimple D, Weiss SJ, Brett M, Ernst AA. An Emergency Department-based Vaccination Program: Overcoming the Barriers for Adults at High Risk for Vaccine-preventable Diseases. Acad Emerg Med 2006;13:922–30. pmid:16902048
- 242. Byrne C, Walsh J, Kola S, Sarma KM. Predicting intention to uptake HINI influenza vaccine in a university sample. Br J Health Psychol 2012;17:582–95. pmid:22107685
- 243. Wan-Arfah N, Norsa’adah B, Naing NN, Zaliha I, Azriani AR, Nik-Rosmawati NH, et al. Knowledge, attitudes and practices on influenza a (H1N1) among Kelantanese schoolchildren. Southeast Asian J Trop Med Public Health 2012;43:1489–501. pmid:23413714
- 244. Peretti-Watel P, Verger P, Raude J, Constant A, Gautier A, Jestin C et al. Dramatic change in public attitudes towards vaccination during the 2009 influenza A(H1N1) pandemic in France. Eurosurveillance 2013;18.
- 245. El Khoury G, Salameh P. Influenza vaccination: A cross-sectional survey of knowledge, attitude and practices among the lebanese adult population. Int J Environ Res Public Health 2015;12:15486–97. pmid:26690189
- 246. Savas E, Tanriverdi D. Knowledge, attitudes and anxiety towards influenza A/H1N1 vaccination of healthcare workers in Turkey. BMC Infect Dis 2010;10.
- 247. Fabry P, Gagneur A, Pasquier J-C. Determinants of A (H1N1) vaccination: cross-sectional study in a population of pregnant women in Quebec. Vaccine 2011;29:1824–9. pmid:21219988
- 248. Lorenz RA, Norris MM, Norton LC, Westrick SC. Factors associated with influenza vaccination decisions among patients with mental illness. Int J Psychiatry Med 2013;46:1–13. pmid:24547606
- 249. Althoff KN, Anastos K, Nelson KE, Celentano DD, Sharp GB, Greenblatt RM, Gange SJ, et al. Predictors of reported influenza vaccination in HIV-infected women in the United States, 2006–2007 and 2007–2008 seasons. Prev Med (Baltim) 2010;50:223–9.
- 250. Hofstetter AM, Barrett A, Stockwell MS. Factors impacting influenza vaccination of urban low-income Latino children under nine years requiring two doses in the 2010–2011 season. J Community Health 2015;40:227–34. pmid:25082482
- 251. Wooten KG, Wortley PM, Singleton JA, Euler GL. Perceptions matter: Beliefs about influenza vaccine and vaccination behavior among elderly white, black and Hispanic Americans. Vaccine 2012;30:6927–34. pmid:22939908
- 252. Lau JTF, Yang X, Tsui HY, Kim JH. Prevalence of influenza vaccination and associated factors among community-dwelling Hong Kong residents of age 65 or above. Vaccine 2006;24:5526–34. pmid:16716461
- 253. Horby PW, Williams A, Burgess MA, Wang H. Prevalence and determinants of influenza vaccination in Australians aged 40 years and over—a national survey. Aust N Z J Public Health 2005;29:35–7. pmid:15782869
- 254. Shono A, Kondo M. Parents’ preferences for seasonal influenza vaccine for their children in Japan. Vaccine 2014;32:5071–6. pmid:25063570
- 255. Santibanez TA, Mootrey GT, Euler GL, Janssen APJ. Behavior and beliefs about influenza vaccine among adults aged 50–64 years. Am J Health Behav 2010;34:77–89 13p. pmid:19663755
- 256. Han YKJ, Michie S, Potts HW, Rubin GJ. Predictors of influenza vaccine uptake during the 2009/10 influenza A H1N1v (‘swine flu’) pandemic: Results from five national surveys in the United Kingdom. Prev Med (Baltim) 2016;84:57–61.
- 257. Newcombe J, Kaur R, Wood N, Seale H, Palasanthiran P, Snelling T. Prevalence and determinants of influenza vaccine coverage at tertiary pediatric hospitals. Vaccine 2014;32:6364–8. pmid:24962754
- 258. Anne-Laure C-B, Jocelyn R, Nathanael L, De-Lambal X, Fabrice C, Michel S. Predictors of IV behaviors during and after the 2009 influenza pandemic in France. Vaccine 2014;32:2007–15. pmid:24434043
- 259. Reiter PL, McRee AL, Gottlieb SL, Markowitz LE, Brewer NT. Uptake of 2009 H1N1 vaccine among adolescent females. Hum Vaccin 2011;7:191–6.
- 260. Schwirian KP. Confidence in government and vaccination willingness in the USA. Health Promot Int 2015;30:213–21. pmid:25369794
- 261. Chuang YC, Huang YL, Tseng KC, Yen CH, Yang LH. Social capital and health-protective behavior intentions in an influenza pandemic. PLoS One 2015;10.
- 262. Boggavarapu S, Sullivan KM, Schamel JT, Frew PM, B S., S K.M., et al. Factors associated with seasonal influenza immunization among church-going older African Americans. Vaccine 2014;32:7085–90. pmid:25444831
- 263. Quinn SC, Parmer J, Freimuth VS, Hilyard KM, Musa D, Kim KH. Exploring communication, trust in government, and vaccination intention later in the 2009 H1N1 pandemic: results of a national survey. Biosecur Bioterror 2013;11:96–106. pmid:23617721
- 264. Straits-Troster KA, Kahwati LC, Kinsinger LS, Orelien J, Burdick MB, Yevich SJ. Racial/ethnic differences in influenza vaccination in the Veterans Affairs Healthcare System. Am J Prev Med 2006;31:375–82. pmid:17046408
- 265. Corace K, Prematunge C, McCarthy A, Nair RC, Roth V, Hayes T, et al. Predicting influenza vaccination uptake among health care workers: what are the key motivators? Am J Infect Control 2013;41:679–84. pmid:23523520
- 266. Rubin GJ, Potts HWW, Michie S. Likely uptake of swine and seasonal flu vaccines among healthcare workers. A cross-sectional analysis of UK telephone survey data. Vaccine 2011;29:2421–8. pmid:21277402
- 267. Thompson MG, Gaglani MJ, Naleway A, Ball S, Henkle EM, Sokolow LZ, et al. The expected emotional benefits of influenza vaccination strongly affect pre-season intentions and subsequent vaccination among healthcare personnel. Vaccine 2012;30:3557–65. pmid:22475860
- 268. Trivalle C, Okenge E, Hamon B, Taillandier J, Falissard B. Factors that influence influenza vaccination among healthcare workers in a French geriatric hospital. Infect Control Hosp Epidemiol 2006;27:1278–80. pmid:17080394
- 269. Verger P, Flicoteaux R, Schwarzinger M, Sagaon-Teyssier L, Peretti-Watel P, Launay O, Moatti JP, et al. Pandemic influenza (A/H1N1) vaccine uptake among French private general practitioners: A cross sectional study in 2010. PLoS One 2012;7.
- 270. Vírseda S, Restrepo MA, Arranz E, Magán-Tapia P, Fernández-Ruiz M, de la Cámara AG, López-Medrano F, et al. Seasonal and Pandemic A (H1N1) 2009 influenza vaccination coverage and attitudes among health-care workers in a Spanish University Hospital. Vaccine 2010;28:4751–7. pmid:20471438
- 271. Wong SYS, Wong ELY, Chor J, Kung K, Chan PKS, Wong C, et al. Willingness to accept H1N1 pandemic influenza vaccine: a cross-sectional study of Hong Kong community nurses. BMC Infect Dis 2010;10:316. pmid:21034439
- 272. Maltezou HC, Dedoukou X, Patrinos S, Maragos A, Poufta S, Gargalianos P et al. Determinants of intention to get vaccinated against novel (pandemic) influenza A H1N1 among health-care workers in a nationwide survey. J Infect 2010;61:252–8. pmid:20600304
- 273. Piccirillo B, Gaeta T. Survey on use of and attitudes toward influenza vaccination among emergency department staff in a New York metropolitan hospital. Infect Control Hosp Epidemiol 2006;27:618–22. pmid:16755483
- 274. Rashid ZZ, Jasme H, Liang HJ, Yusof MM, Sharani ZZM, Mohamad M, et al. Influenza vaccination uptake among healthcare workers at a Malaysian teaching hospital. Southeast Asian J Trop Med Public Health 2015;46:215–25. pmid:26513924
- 275. Abu-Gharbieh E, Fahmy S, Rasool BA, Khan S. Influenza vaccination: Healthcare workers attitude in three middle east countries. Int J Med Sci 2010;7:319–25. pmid:20922053
- 276. Alkuwari MG, Aziz NA, Nazzal ZAS, Al-Nuaimi SA. Pandemic influenza A/H1N1 vaccination uptake among health care workers in Qatar: motivators and barriers. Vaccine 2011;29:2206–11. pmid:21462430
- 277. Askarian M, Khazaeipour Z, McLaws ML. Influenza vaccination uptake among students and clinical staff of a university in Iran. Int J Infect Dis 2009;13:476–82. pmid:19046912
- 278. Barriere J, Vanjak D, Kriegel I, Otto J, Peyrade F, Esteve M, et al. Acceptance of the 2009 A(H1N1) influenza vaccine among hospital workers in two French cancer centers. Vaccine 2010;28:7030–4. pmid:20817011
- 279. Bonaccorsi G, Lorini C, Santomauro F, Guarducci S, Pellegrino E, Puggelli F, et al. Predictive factors associated with the acceptance of pandemic and seasonal influenza vaccination in health care workers and students in Tuscany, Central Italy. Hum Vaccin Immunother 2013;9:2603–12. pmid:23954990
- 280. Bouadma L, Barbier F, Biard L, Esposito-Farese M, Le Corre B, Macrez A, et al. Personal decision-making criteria related to seasonal and pandemic A(H1N1) influenza-vaccination acceptance among French healthcare workers. PLoS One 2012;7:e38646. pmid:22848342
- 281. Costantino C, Mazzucco W, Azzolini E, Baldini C, Bergomi M, Biafiore AD, et al. Influenza vaccination coverage among medical residents: an Italian multicenter survey. Hum Vaccin Immunother 2014;10:1204–10. pmid:24603089
- 282. Dedoukou X, Nikolopoulos G, Maragos A, Giannoulidou S, Maltezou HC. Attitudes towards vaccination against seasonal influenza of health-care workers in primary health-care settings in Greece. Vaccine 2010;28:5931–3. pmid:20637760
- 283. Di Gregori V, Franchino G, Marcantoni C, Simone B, Costantino C. Logistic regression of attitudes and coverage for influenza vaccination among Italian Public Health medical residents. J Prev Med Hyg 2014;55:152–7. pmid:26137789
- 284. Dubnov J, Kassabri W, Bisharat B, Rishpon S. Influenza vaccination coverage determinants among employees of the Nazareth Hospital in Israel. Isr Med Assoc J 2010;12:338–41. pmid:20928986
- 285. Machowicz R, Wyszomirski T, Ciechanska J, Mahboobi N, Wnekowicz E, Obrowski M, et al. Knowledge, attitudes, and influenza vaccination of medical students in Warsaw, Strasbourg, and Teheran. Eur J Med Res 2010;15 Suppl 2:235–40.
- 286. Ortiz Arjona MA, Abd Elaziz KM, Caballero Lanzas JM, Allam MF. Coverage and side effects of influenza A(H1N1) 2009 monovalent vaccine among primary health care workers. Vaccine 2011;29:6366–8. pmid:21840463
- 287. Schult TM, Awosika ER, Hodgson MJ, Hirsch PR, Nichol KL, Dyrenforth SR, et al. Innovative approaches for understanding seasonal influenza vaccine declination in healthcare personnel support development of new campaign strategies. Infect Control Hosp Epidemiol 2012;33:924–31. pmid:22869267
- 288. To KW, Lee S, Chan TO, Lee SS. Exploring determinants of acceptance of the pandemic influenza A (H1N1) 2009 vaccination in nurses. Am J Infect Control 2010;38:623–30. pmid:20566229
- 289. Pulcini C, Massin S, Launay O, Verger P. Factors associated with vaccination for hepatitis B, pertussis, seasonal and pandemic influenza among French general practitioners: A 2010 survey. Vaccine 2013;31:3943–9. pmid:23806242
- 290. Valour F, Cotte L, Voirin N, Godinot M, Ader F, Ferry T, et al. Vaccination coverage against hepatitis A and B viruses, Streptococcus pneumoniae, seasonal flu, and A(H1N1)2009 pandemic influenza in HIV-infected patients. Vaccine 2014;32:4558–64. pmid:24951870
- 291. Vinograd I, Baslo R, Eliakim-Raz N, Farbman L, Taha A, Sakhnini A, et al. Factors associated with influenza vaccination among adult cancer patients: a case-control study. Clin Microbiol Infect 2014;20:899–905. pmid:24655107
- 292. Çamurdan MO, Çamurdan AD, Beyazova U, Bideci A. The rate of seasonal influenza vaccination in diabetic children, the effect of recommendation and the factors influencing the acceptance of recommendation: An interventional study. Balkan Med J 2012;29:434–9. pmid:25207049
- 293. Peleg N, Zevit N, Shamir R, Chodick G, Levy I. Seasonal influenza vaccination rates and reasons for non-vaccination in children with gastrointestinal disorders. Vaccine 2015;33:182–6. pmid:25444802
- 294. Cotte L, Voirin N, Richard C, Brochier C, Schlienger I, Lack P, et al. Factors associated with pandemic influenza A/H1N1 vaccine coverage in a French cohort of HIV-infected patients. Vaccine 2011;29:5638–44. pmid:21699948
- 295. Sbidian E, Tubach F, Pasquet B, Paul C, Jullien D, Sid-Mohand D, et al. Factors associated with 2009 monovalent H1N1 vaccine coverage: a cross sectional study of 1,308 patients with psoriasis in France. Vaccine 2012;30:5703–7. pmid:22828586
- 296. Freund R, Le Ray C, Charlier C, Avenell C, Truster V, Treluyer J-M, et al. Determinants of non-vaccination against pandemic 2009 H1N1 influenza in pregnant women: a prospective cohort study. PLoS One 2011;6:e20900. pmid:21695074
- 297. Sammon CJ, McGrogan A, Snowball J, De Vries CS. Pandemic influenza vaccination during pregnancy: An investigation of vaccine uptake during the 2009/10 pandemic vaccination campaign in Great Britain. Hum Vaccines Immunother 2013;9:917–23.
- 298. Liu N, Sprague AE, Yasseen AS 3rd, Fell DB, Wen S-W, Smith GN, et al. Vaccination patterns in pregnant women during the 2009 H1N1 influenza pandemic: a population-based study in Ontario, Canada. Can J Public Health 2012;103:e353–8. pmid:23617987
- 299. Daley MF, Crane LA, Chandramouli V, Beaty BL, Barrow J, Allred N, et al. Influenza among healthy young children: changes in parental attitudes and predictors of immunization during the 2003 to 2004 influenza season. Pediatrics 2006;117:e268–77. pmid:16452334
- 300. Jiménez-García R, Esteban-Vasallo MD, Rodríguez-Rieiro C, Hernandez-Barrera V, Domínguez-Berjón MF, Carrasco Garrido P, Astray-Mochales J, et al. Coverage and predictors of vaccination against 2012/13 seasonal influenza in Madrid, Spain Analysis of population-based computerized immunization registries and clinical records. Hum Vaccines Immunother 2014;10:449–55.
- 301. Milman U, Ben-Moshe S, Hermoni D. The role of the patient care team in elderly people decision on influenza vaccination. Patient Educ Couns 2005;58:203–8. pmid:16009298
- 302. Mamelund SE, Bergsaker MAR. Vaccine history, gender and influenza vaccination in a household context. Vaccine 2011;29:9441–50. pmid:22027482
- 303. Li Y-C, Liu C-M. Threat-responsiveness and the decision to obtain free influenza vaccinations among the older adults in Taiwan. BMC Public Health 2009;9:275. pmid:19646246
- 304. Uddin M, Cherkowski GC, Liu G, Zhang J, Monto AS, Aiello AE. Demographic and socioeconomic determinants of influenza vaccination disparities among university students. J Epidemiol Community Health 2010;64:808–13. pmid:19828514
- 305. Rodas JR, Lau CH, Zhang ZZ, Griffiths SM, Luk WC, Kim JH, et al. Exploring predictors influencing intended and actual acceptability of the A/H1N1 pandemic vaccine: A cohort study of university students in Hong Kong. Public Health 2012;126:1007–12. pmid:23141148
- 306. Szucs TD, Müller D. Influenza vaccination coverage rates in five European countries—A population-based cross-sectional analysis of two consecutive influenza seasons. Vaccine 2005;23:5055–63. pmid:16046035
- 307. Vaux S, Van Cauteren D, Guthmann J-P, Le Strat Y, Vaillant V, de Valk H, et al. Influenza vaccination coverage against seasonal and pandemic influenza and their determinants in France: a cross-sectional survey. BMC Public Health 2011;11:30. pmid:21226919
- 308. Walter D, Böhmer MM, an der Heiden M, Reiter S, Krause G, Wichmann O. Monitoring pandemic influenza A(H1N1) vaccination coverage in Germany 2009/10—Results from thirteen consecutive cross-sectional surveys. Vaccine 2011;29:4008–12. pmid:21463683
- 309. Galarce EM, Minsky S, Viswanath K. Socioeconomic status, demographics, beliefs and A(H1N1) vaccine uptake in the United States. Vaccine 2011;29:5284–9. pmid:21621577
- 310. Rodriguez-Rieiro C, Esteban-Vasallo MD, Dominguez-Berjon MF, Astray-Mochales J, Iniesta-Fornies D, Barranco-Ordonez D, et al. Coverage and predictors of vaccination against 2009 pandemic H1N1 influenza in Madrid, Spain. Vaccine 2011;29:1332–8. pmid:21182996
- 311. Eastwood K, Durrheim DN, Jones A, Butler M. Acceptance of pandemic (H1N1) 2009 influenza vaccination by the Australian public. Med J Aust 2010;192:33–6. pmid:20047546
- 312. Heo JY, Chang SH, Go MJ, Kim YM, Gu SH, Chun BC. Risk Perception, Preventive Behaviors, and Vaccination Coverage in the Korean Population during the 2009–2010 Pandemic Influenza A (H1N1): Comparison between High-Risk Group and Non-High-Risk Group. PLoS One 2013;8.
- 313. Pfeil A, Mutsch M, Hatz C, Szucs TD. A cross-sectional survey to evaluate knowledge, attitudes and practices (KAP) regarding seasonal influenza vaccination among European travellers to resource-limited destinations. BMC Public Health 2010;10:402. pmid:20609230
- 314. Tsai Y-Y, Lee J-J, Hsieh W-H. Determinants of the public intent to receive the seasonal influenza vaccine and protective behaviors: a population-based study in Taiwan. Vaccine 2014;32:6667–75. pmid:25240751
- 315. Lin CJ, Nowalk MP, Toback SL, Rousculp MD, Raymund M, Ambrose CS, et al. Importance of vaccination habit and vaccine choice on influenza vaccination among healthy working adults. Vaccine 2010;28:7706–12. pmid:20638452
- 316. Kee SY, Lee JS, Cheong HJ, Chun BC, Song JY, Choi WS, Kim WJ, et al. Influenza vaccine coverage rates and perceptions on vaccination in South Korea. J Infect 2007;55:273–81. pmid:17602750
- 317. Wada K, Smith DR. Influenza vaccination uptake among the working age population of Japan: results from a national cross-sectional survey. PLoS One 2013;8:e59272. pmid:23555010
- 318. Biro A. Determinants of H1N1 vaccination uptake in England. Prev Med (Baltim) 2013;57:140–2.
- 319. Yi S, Nonaka D, Nomoto M, Kobayashi J, Mizoue T. Predictors of the uptake of A (H1N1) influenza vaccine: Findings from a population-based longitudinal study in Tokyo. PLoS One 2011;6.
- 320. Painter JE, Sales JM, Pazol K, Wingood GM, Windle M, Orenstein WA, et al. Psychosocial correlates of intention to receive an influenza vaccination among rural adolescents. Health Educ Res 2010;25:853–64. pmid:20603385
- 321. Jimenez-Garcia R, Arinez-Fernandez MC, Garcia-Carballo M, Hernandez-Barrera V, de Miguel AG, Carrasco-Garrido P. Influenza vaccination coverage and related factors among Spanish patients with chronic obstructive pulmonary disease. Vaccine 2005;23:3679–86. pmid:15882528
- 322. Winston CA, Wortley PM, Lees KA. Factors associated with vaccination of Medicare beneficiaries in five U.S. communities: results from the Racial and Ethnic Adult Disparities in Immunization Initiative Survey, 2003. J Am Geriatr Soc 2006;54:303–310 8p. pmid:16460383
- 323. Njuguna H, Ahmed J, Oria PA, Arunga G, Williamson J, Kosgey A, et al. Uptake and effectiveness of monovalent influenza A (H1N1) pandemic 2009 vaccine among healthcare personnel in Kenya, 2010. Vaccine 2013;31:4662–7. pmid:23859843
- 324. Mendoza-Sassi RA, Cesar JA, Cagol JM, Duarte IA, Friedrich LM, Santos VK dos, et al. 2010 A(H1N1) vaccination in pregnant women in Brazil: identifying coverage and associated factors. Cad Saude Publica 2015;31:1247–56. pmid:26200372
- 325. Weaver FM, Smith B, LaVela S, Wallace C, Evans CT, Hammond M, et al. Interventions to increase influenza vaccination rates in veterans with spinal cord injuries and disorders. J Spinal Cord Med 2007;30:10–9. pmid:17387805
- 326. Kee SY, Lee JS, Cheong HJ, Chun BC, Song JY, Choi WS, et al. Influenza vaccine coverage rates and perceptions on vaccination in South Korea. J Infect 2007;55:273–81. pmid:17602750
- 327. Shono A, Kondo M. Factors associated with seasonal influenza vaccine uptake among children in Japan. BMC Infect Dis 2015;15:72. pmid:25886607
- 328. Milunic SL, Quilty JF, Super DM, Noritz GH. Patterns of influenza vaccination among medical students. Infect Control Hosp Epidemiol 2010;31:85–8. pmid:19951199
- 329. Cozza V, Alfonsi V, Rota MC, Paolini V, Ciofi degli Atti ML. Promotion of influenza vaccination among health care workers: findings from a tertiary care children’s hospital in Italy. BMC Public Health 2015;15:697. pmid:26204896
- 330. Polat HH, Yalçin AN, Öncel S. Influenza vaccination; Rates, knowledge and the attitudes of physicians in a university hospital. Turkiye Klin J Med Sci 2010;30:48–53.
- 331. Kadi Z, Atif ML, Brenet A, Izoard S, Astagneau P. Barriers of influenza vaccination in health care personnel in France. Am J Infect Control 2015.
- 332. Dominguez A, Godoy P, Castilla J, Maria Mayoral J, Soldevila N, Torner N, et al. Knowledge of and attitudes to influenza in unvaccinated primary care physicians and nurses. Hum Vaccin Immunother 2014;10:2378–86. pmid:25424945
- 333. Lee SI, Aung EM, Chin IS, Hing JW, Mummadi S, Palaniandy GD et al. Factors affecting medical students’ uptake of the 2009 pandemic influenza a (H1N1) vaccine. Influenza Res Treat 2012;2012.
- 334. Kaufman J, Davis J, Krause V. Influenza immunisation of doctors at an Australian tertiary hospital: immunisation rate and factors contributing to uptake. Commun Dis Intell Q Rep 2008;32:443–8. pmid:19374273
- 335. Ozer A, Arikan DC, Kirecci E, Ekerbicer HC. Status of pandemic influenza vaccination and factors affecting it in pregnant women in Kahramanmaras, an eastern Mediterranean city of Turkey. PLoS One 2010;5:e14177. pmid:21152073
- 336. Humiston SG, Lerner EB, Hepworth E, Blythe T, Goepp JG. Parent opinions about universal influenza vaccination for infants and toddlers. Arch Pediatr Adolesc Med 2005;159:108–12. pmid:15699302
- 337. Lau JTF, Au DWH, Tsui HY, Choi KC. Prevalence and determinants of influenza vaccination in the Hong Kong Chinese adult population. Am J Infect Control 2012;40:e225–7. pmid:22743046
- 338. Chanel O, Luchini S, Massoni S, Vergnaud J-C. Impact of information on intentions to vaccinate in a potential epidemic: Swine-origin Influenza A (H1N1). Soc Sci Med 2011;72:142–8. pmid:21163566
- 339. Rodas JR, Lau CH, Zhang ZZ, Griffiths SM, Luk WC, Kim JH. Exploring predictors influencing intended and actual acceptability of the A/H1N1 pandemic vaccine: a cohort study of university students in Hong Kong. Public Health 2012;126:1007–12. pmid:23141148
- 340. Yeung MP, Ng SK-C, Tong ETF, Chan SS-K, Coker R. Factors associated with uptake of influenza vaccine in people aged 50 to 64 years in Hong Kong: a case-control study. BMC Public Health 2015;15:617. pmid:26148496
- 341. Shahrabani S, Benzion U. Workplace vaccination and other factors impacting influenza vaccination decision among employees in Israel. Int J Environ Res Public Health 2010;7:853–69. pmid:20617008
- 342. Zairina AR, Nooriah MS, Yunus AM. Knowledge and practices towards influenza A (H1N1) among adults in three residential areas in Tampin Negeri Sembilan: a cross sectional survey. Med J Malaysia 2011;66:207–13. pmid:22111442
- 343. Vaux S, Noel D, Fonteneau L, Guthmann J-P, Levy-Bruhl D. Influenza vaccination coverage of healthcare workers and residents and their determinants in nursing homes for elderly people in France: a cross-sectional survey. BMC Public Health 2010;10:159. pmid:20338028
- 344. Betsch C, Wicker S. E-health use, vaccination knowledge and perception of own risk: Drivers of vaccination uptake in medical students. Vaccine 2012;30:1143–8. pmid:22192850
- 345. Li Z, Doan Q, Dobson S. Determinants of influenza immunization uptake in Canadian youths. Vaccine 2010;28:3462–6. pmid:20199757
- 346. Sammon CJ, McGrogan A, Snowball J, De Vries CS. Factors associated with uptake of seasonal and pandemic influenza vaccine among clinical risk groups in the UK: An analysis using the General Practice Research Database. Vaccine 2012;30:2483–9. pmid:22133511
- 347. Yang HJ, Cho S-I. Influenza vaccination coverage among adults in Korea: 2008–2009 to 2011–2012 seasons. Int J Environ Res Public Health 2014;11:12162–73. pmid:25429683
- 348. Chiatti C, Barbadoro P, Marigliano A, Ricciardi A, Di Stanislao F, Prospero E. Determinants of influenza vaccination among the adult and older Italian population with chronic obstructive pulmonary disease: a secondary analysis of the multipurpose ISTAT survey on health and health care use. Hum Vaccin 2011;7:1021–5. pmid:21941094
- 349. Rodriguez-Rieiro C, Dominguez-Berjon MF, Esteban-Vasallodominguez-Berjon MD, Cuadrado AR, Carrasco-Garrido P, Jimenez-Garcia R. Coverage and predictors of influenza vaccine uptake among adults aged 16 to 59 years suffering from a chronic condition in Madrid, Spain. Hum Vaccin 2011;7:557–62. pmid:21441784
- 350. Lopez-de-Andres A, Carrasco-Garrido P, Hernandez-Barrera V, de Miguel AG, Jimenez-Garcia R, López-de-Andrés A, et al. Coverages and factors associated with influenza vaccination among subjects with chronic respiratory diseases in Spain. Eur J Public Health 2008;18:173–177 5p. pmid:17875577
- 351. Dower J, Donald M, Begum N, Vlack S, Ozolins I. Patterns and determinants of influenza and pneumococcal immunisation among adults with chronic disease living in Queensland, Australia. Vaccine 2011;29:3031–7. pmid:21335033
- 352. Santos-Sancho JM, Jimenez-Trujillo I, Hernandez-Barrera V, Lopez-de Andres A, Carrasco-Garrido P, Ortega-Molina P, et al. Influenza vaccination coverage and uptake predictors among Spanish adults suffering COPD. Hum Vaccin Immunother 2012;8:938–45. pmid:22485047
- 353. Jimenez-Garcia R, Hernandez-Barrera V, de Andres AL, Jimenez-Trujillo I, Esteban J, Gil A, et al. Predictors of influenza vaccination uptake among adults with a history of heart attack. Hum Vaccin 2010;6:566–71. pmid:20519968
- 354. Jimenez-Garcia R, Hernandez-Barrera V, Carrasco Garrido P, del Pozo SV-F, de Miguel AG. Influenza vaccination among cardiovascular disease sufferers in Spain: related factors and trend, 1993–2003. Vaccine 2006;24:5073–82. pmid:16621172
- 355. Chiatti C, Barbadoro P, Lamura G, Pennacchietti L, Di Stanislao F, D’Errico MM, et al. Influenza vaccine uptake among community-dwelling Italian elderly: results from a large cross-sectional study. BMC Public Health 2011;11:207. pmid:21457562
- 356. Xakellis GC. Predictors of influenza immunization in persons over age 65. J Am Board Fam Pract 2005;18:426–33. pmid:16148255
- 357. Chi R-C, Reiber GE, Neuzil KM. Influenza and pneumococcal vaccination in older veterans: results from the behavioral risk factor surveillance system. J Am Geriatr Soc 2006;54:217–23. pmid:16460371
- 358. Dip RM, Cabrera MAS. Influenza vaccination in non-institutionalized elderly: a population-based study in a medium-sized city in Southern Brazil. Cad Saude Publica 2010;26:1035–44. pmid:20563403
- 359. de Andres AL, Garrido PC, Hernandez-Barrera V, Del Pozo SV-F, de Miguel AG, Jimenez-Garcia R. Influenza vaccination among the elderly Spanish population: trend from 1993 to 2003 and vaccination-related factors. Eur J Public Health 2007;17:272–7. pmid:17071634
- 360. Schmitz H, Wubker A. What determines influenza vaccination take-up of elderly Europeans? Health Econ 2011;20:1281–97. pmid:20949645
- 361. Takayama M, Wetmore CM, Mokdad AH. Characteristics associated with the uptake of influenza vaccination among adults in the United States. Prev Med (Baltim) 2012;54:358–62.
- 362. Hirdes JP, Dalby DM, Steel RK, Carpenter GI, Bernabei R, Morris JN, et al. Predictors of influenza immunization among home care clients in Ontario. Can J Public Health 2006;97:335–9. pmid:16967757
- 363. Polisena J, Chen Y, Manuel D. The proportion of influenza vaccination in Ontario, Canada in 2007/2008 compared with other provinces. Vaccine 2012;30:1981–5. pmid:22245605
- 364. Nowalk MP, Balasubramani GK, Schaffer M, Lieberman RH, Eng H, Kyle S, et al. Intention to receive influenza vaccine after an acute respiratory illness. Am J Health Behav 2015;39:573–81. pmid:26018106
- 365. Lee K-C, Han K, Kim JY, Nam GE, Han B-D, Shin K-E, et al. Socioeconomic status and other related factors of seasonal influenza vaccination in the South Korean adult population based on a nationwide cross-sectional study. PLoS One 2015;10:e0117305. pmid:25646847
- 366. Dyda A, MacIntyre CR, McIntyre P, Newall AT, Banks E, Kaldor J et al. Factors associated with influenza vaccination in middle and older aged Australian adults according to eligibility for the national vaccination program. Vaccine 2015;33:3299–305. pmid:26036944
- 367. Barbadoro P, Marigliano A, Di Tondo E, Chiatti C, Di Stanislao F, D’Errico MM et al. Determinants of influenza vaccination uptake among Italian healthcare workers. Hum Vaccines Immunother 2013;9:911–6.
- 368. Sambamoorthi U, Findley PA. Who are the elderly who never receive influenza immunization? Prev Med (Baltim) 2005;40:469–78.
- 369. Lu P, Ding H, Black CL. H1N1 and seasonal influenza vaccination of U.S. healthcare personnel, 2010. Am J Prev Med 2012;43:282–92. pmid:22898121
- 370. Stafford KA, Sorkin JD, Steinberger EK. Influenza vaccination among cancer survivors: disparities in prevalence between blacks and whites. J Cancer Surviv 2013;7:183–90. pmid:23315210
- 371. Mayo Montero E, Hernandez-Barrera V, Carrasco-Garrido P, Gil de Miguel A, Jimenez-Garcia R, Montero EM, et al. Influenza vaccination among persons with chronic respiratory diseases: coverage, related factors and time-trend, 1993–2001. Public Health 2007;121:113–21. pmid:17217975
- 372. Jimenez-Garcia R, Hernandez-Barrera V, Carrasco-Garrido P, Lopez de Andres A, de Miguel AG. Predictors of influenza vaccination in adults with chronic bronchitis. Respir Med 2009;103:1518–25. pmid:19428233
- 373. Damiani G, Federico B, Visca M, Agostini F, Ricciardi W. The impact of socioeconomic level on influenza vaccination among Italian adults and elderly: A cross-sectional study. Prev Med (Baltim) 2007;45:373–9.
- 374. Jimenez-Garcia R, Carrasco-Garrido P, Hernandez-Barrera V, de Miguel AG. Influenza vaccination coverage and predictors for vaccination among Spanish healthcare workers. Hum Vaccin 2007;3:33–6. pmid:17264683
- 375. Sato APS, Antunes JLF, Moura RF, de Andrade FB, Duarte YAO, Lebrão ML.Factors associated to vaccination against influenza among elderly in a large Brazilian metropolis. PLoS One 2015;10:e0123840. pmid:25874953
- 376. Chiatti C, Di Rosa M, Barbadoro P, Lamura G, Di Stanislao F, Prospero E. Socioeconomic determinants of influenza vaccination among older adults in Italy. Prev Med (Baltim) 2010;51:332–3.
- 377. Damiani G, Federico B, Visca M, Agostini F, Ricciardi W. The impact of socioeconomic level on influenza vaccination among Italian adults and elderly: a cross-sectional study. Prev Med (Baltim) 2007;45:373–9.
- 378. Andres AL de, Garrido PC, Hernandez-Barrera V, Pozo SV-F del, Miguel AG de, Jimenez-Garcia R, et al. Influenza vaccination among the elderly Spanish population: trend from 1993 to 2003 and vaccination-related factors. Eur J Public Health 2007;17:272–7. pmid:17071634
- 379. Lee KC, Han K, Kim JY, Nam GE, Han BD, Shin KE et al. Socioeconomic status and other related factors of seasonal influenza vaccination in the South Korean adult population based on a nationwide cross-sectional study. PLoS One 2015;10.
- 380. La Torre G, Iarocci G, Cadeddu C, Boccia A. Influence of sociodemographic inequalities and chronic conditions on influenza vaccination coverage in Italy: results from a survey in the general population. Public Health 2010;124:690–7. pmid:21035825
- 381. Hobbs JL, Buxton JA. Influenza immunization in Canada’s low-income population. BMC Public Health 2014;14:740. pmid:25048163
- 382. LaVela SL, Goldstein B, Etingen B, Miskevics S, Weaver FM, L S., et al. Factors associated with H1N1 influenza vaccine receipt in a high-risk population during the 2009–2010 H1N1 influenza pandemic. Top Spinal Cord Inj Rehabil 2012;18:306–14. pmid:23459437
- 383. Lu P, Bridges CB, Euler GL, Singleton JA. Influenza vaccination of recommended adult populations, U.S., 1989–2005. Vaccine 2008;26:1786–93. pmid:18336965
- 384. Mendiola J, Do-Reynoso V, Gonzalez M. Generation status as a determinant of influenza vaccination among Mexican-identified adults in California, 2011–12. Prev Med Reports 2016;3:25–9.
- 385. Yun HS, Min YW, Chang DK, Rhee P-L, Kim JJ, Rhee JC, et al. Factors associated with vaccination among inflammatory bowel disease patients in Korea. Korean J Gastroenterol 2013;61:203–8. pmid:23624734
- 386. Haroon M, Adeeb F, Eltahir A, Harney S. The uptake of influenza and pneumococcal vaccination among immunocompromised patients attending rheumatology outpatient clinics. Joint Bone Spine 2011;78:374–7. pmid:21169045
- 387. LaVela S, Goldstein B, Etingen B, Miskevics S, Weaver F. Factors associated with H1N1 influenza vaccine receipt in a high-risk population during the 2009–2010 H1N1 influenza pandemic. Top Spinal Cord Inj Rehabil 2012;18:306–14. pmid:23459437
- 388. Shin DW, Kim Y, Park JH, Cho J, Jho HJ, Yang H-K, et al. Practices and predictors of 2009 H1N1 vaccination in cancer patients: a nationwide survey in Korea. Influenza Other Respi Viruses 2012;6:e120–8.
- 389. Ma KK, Schaffner W, Colmenares C, Howser J, Jones J, Poehling KA. Influenza vaccinations of young children increased with media coverage in 2003. Pediatrics 2006;117:e157–63. pmid:16452325
- 390. Yen CF, Hsu SW, Loh CH, Fang WH, Wu CL, Chu CM et al. Analysis of seasonal influenza vaccine uptake among children and adolescents with an intellectual disability. Res Dev Disabil 2012;33:704–10. pmid:22188794
- 391. Andersen RM. Revisiting the Behavioral Model and Access to Medical Care: Does it Matter? J Health Soc Behav 1995;36:1–10. pmid:7738325
- 392. Hochbaum G, Rosenstock I, Kegels S. Health Belief Model. vol. 4. 1952.
- 393. Hopman CE, Riphagen-Dalhuisen J, Looijmans-van den Akker I, Frijstein G, Van der Geest-Blankert ADJ, Danhof-Pont MB et al. Determination of factors required to increase uptake of influenza vaccination among hospital-based healthcare workers. J Hosp Infect 2011;77:327–331 5p. pmid:21316803
- 394. Kelly DA, Macey DJ, Mak DB. Annual influenza vaccination: Uptake, barriers, and enablers among student health care providers at the University of Notre Dame Australia, Fremantle. Hum Vaccines Immunother 2014;10:1930–4.
- 395. Kelly DA, Macey DJ, Mak DB. Annual influenza vaccination: Uptake, barriers, and enablers among student health care providers at the University of Notre Dame Australia, Fremantle. Intern Med J 2014;44:37–8.
- 396. Hou Z, Chang J, Yue D, Fang H, Meng Q, Zhang Y. Determinants of willingness to pay for self-paid vaccines in China. Vaccine 2014;32:4471–7. pmid:24968160
- 397. Guiney H, Walton D. New Zealanders’ self-reported uptake and attitudes towards the influenza vaccine in 2012. N Z Med J 2014;127:28–34. pmid:25146859
- 398. Takayama M, Gillespie CW, Mokdad AH. Health-care access and uptake of influenza vaccination among pregnant women in the USA: a cross-sectional survey. Lancet 2013;381:141.
- 399. Achtymichuk KA, Johnson JA, Al Sayah F, Eurich DT. Characteristics and health behaviors of diabetic patients receiving influenza vaccination. Vaccine 2015;33:3549–55. pmid:26044494
- 400. Soyer OU, Hudaverdiyev S, Civelek E, Isik E, Karabulut E, Kocabas C, et al. Parental perspectives on influenza vaccination in children with asthma. Pediatr Pulmonol 2011;46:139–44. pmid:20812246
- 401. Uwemedimo OT, Findley SE, Andres R, Irigoyen M, Stockwell MS. Determinants of influenza vaccination among young children in an inner-city community. J Community Health 2012;37:663–72. pmid:22045471
- 402. Poehling KA, Fairbrother G, Zhu Y, Donauer S, Ambrose S, Edwards KM et al. Practice and Child Characteristics Associated With Influenza Vaccine Uptake in Young Children. Pediatrics 2010;126:665–673 9p. pmid:20819893
- 403. Ortiz JR, Neuzil KM, Victor JC, Aitken ML, Goss CH. Predictors of influenza vaccination in the cystic fibrosis foundation patient registry, 2006 through 2007. Chest 2010;138:1448–1455 8p. pmid:20495106
- 404. Ortiz JR, Neuzil KM, Victor JC, Aitken ML, Goss CH, , et al. Predictors of influenza vaccination in the cystic fibrosis foundation patient registry, 2006 through 2007. Chest 2010;138:1448–55. pmid:20495106
- 405. Lu PJ, O’Halloran A, Williams WW, Lindley MC, Farrall S, Bridges CB. Racial and ethnic disparities in vaccination coverage among adult populations in the U.S. Vaccine 2015;33:D83–91. pmid:26615174
- 406. Lu PJ, Singleton JA, Rangel MC, Wortley PM, Bridges CB. Influenza vaccination trends among adults 65 years or older in the United States, 1989–2002. Arch Intern Med 2005;165:1849–56. pmid:16157828
- 407. Burns VE, Ring C, Carroll D. Factors influencing influenza vaccination uptake in an elderly, community-based sample. Vaccine 2005;23:3604–8. pmid:15855020
- 408. Souto Barreto P de, Lapeyre-Mestre M, Vellas B, Rolland Y. Indicators of influenza and pneumococcal vaccination in French nursing home residents in 2011. Vaccine 2014;32.
- 409. Singleton JA, Santibanez TA, Wortley PM. Influenza and pneumococcal vaccination of adults aged > or = 65: racial/ethnic differences. Am J Prev Med 2005;29:412–20. pmid:16376704
- 410. Moura RF, de Andrade FB, Oliveira Duarte YA, Lebrao ML, Ferreira Antunes JL. Factors associated with adherence to influenza vaccination among non-institutionalized elderly in Sao Paulo, Brazil. Cad Saude Publica 2015;31.
- 411. Lau JT, Kim JH, Yang X, Tsui HY. Cross-sectional and longitudinal factors predicting influenza vaccination in Hong Kong Chinese elderly aged 65 and above. J Infect 2008;56:460–8. pmid:18442855
- 412. Daniels NA, Gildengorin G, Nguyen TT, Liao Y, Luong T-N, McPhee SJ. Influenza and pneumococcal vaccination rates among Vietnamese, Asian, and non-Hispanic white Americans. J Immigr Minor Health 2010;12:370–6. pmid:18839311
- 413. Crawford VLS, O’Hanlon A, McGee H. The effect of patient characteristics upon uptake of the influenza vaccination: a study comparing community-based older adults in two healthcare systems. Age Ageing 2011;40:35–41. pmid:21148323
- 414. Wang J, Munshi KD, Hong SH. Racial and ethnic disparities in influenza vaccinations among community pharmacy patients and non-community pharmacy respondents. Res Social Adm Pharm 2014;10:126–40. pmid:23706653
- 415. Phillips-Caesar E, Coady MH, Blaney S, Ompad DC, Sisco S, Glidden K, et al. Predictors of influenza vaccination in an urban community during a national shortage. J Health Care Poor Underserved 2008;19:611–24. pmid:18469431
- 416. Jiménez-García R, Hernández-Barrera V, de Andres AL, Jimenez-Trujillo I, Esteban-Hernández J, Carrasco-Garrido P. Gender influence in influenza vaccine uptake in Spain: Time trends analysis (1995–2006). Vaccine 2010;28:6169–75. pmid:20659518
- 417. Jiménez-García R, Jimenez I, PC G, Hernández-Barrera V, AL de A, JL del B, et al. Coverage and predictors of influenza vaccination among adults with diabetes in Spain. Diabetes Res Clin Pract 2008;79:510–7. pmid:18035444
- 418. Carrasco-Garrido P, de Andres AL, Hernandez-Barrera V, de Miguel AG, Jimenez-Garcia R. Patient’s perceptions and information provided by the public health service are predictors for influenza vaccine uptake. Hum Vaccin 2009;5:839–42. pmid:19901549
- 419. Otieno NA, Nyawanda BO, Audi A, Emukule G, Lebo E, Bigogo G, et al. Demographic, socio-economic and geographic determinants of seasonal influenza vaccine uptake in rural western Kenya, 2011. Vaccine 2014;32:6699–704. pmid:24462406
- 420. Bryant WK, Ompad DC, Sisco S, Blaney S, Glidden K, Phillips E et al. Determinants of influenza vaccination in hard-to-reach urban populations. Prev Med (Baltim) 2006;43:60–70 11p.
- 421. Chambers CT, Buxton JA, Koehoorn M. Consultation with health care professionals and influenza immunization among women in contact with young children. Can J Public Health 2010;101:15–9. pmid:20364531
- 422. Shroufi A, Copping J, Musonda P, Vivancos R, Langden V, Armstrong S, et al. Influenza vaccine uptake among staff in care homes in Nottinghamshire: a random cluster sample survey. Public Health 2009;123:645–9. pmid:19875140
- 423. Lindley MC, Groom A V, Wortley PM, Euler GL, MC L, AV G, et al. Status of influenza and pneumococcal vaccination among older American Indians and Alaska Natives. Am J Public Health 2008;98:932–8. pmid:18381996
- 424. Jasek JP. Having a primary care provider and receipt of recommended preventive care among men in New York City. Am J Mens Health 2011;5:225–35. pmid:20798146
- 425. Kraut A, Graff L, McLean D. Behavioral change with influenza vaccination: factors influencing increased uptake of the pandemic H1N1 versus seasonal influenza vaccine in health care personnel. Vaccine 2011;29:8357–63. pmid:21888939
- 426. Mak DB, Regan AK, Joyce S, Gibbs R, Effler P V. Antenatal care provider’s advice is the key determinant of influenza vaccination uptake in pregnant women. Aust N Z J Obstet Gynaecol 2015;55:131–7. pmid:25557858
- 427. Arriola CS, Vasconez N, Thompson M, Mirza S, Moen AC, Bresee J. et al. Factors associated with a successful expansion of influenza vaccination among pregnant women in Nicaragua. Vaccine 2016.
- 428. Maher L, Hope K, Torvaldsen S, Lawrence G, Dawson A, Wiley K, et al. Influenza vaccination during pregnancy: coverage rates and influencing factors in two urban districts in Sydney. Vaccine 2013;31:5557–64. pmid:24076176
- 429. Poeppl W, Lagler H, Raderer M, Sperr WR, Zielinski C, Herkner H, et al. Influenza vaccination perception and coverage among patients with malignant disease. Vaccine 2015;33:1682–7. pmid:25720791
- 430. Lyn-Cook R, Halm EA, Wisnivesky JP. Determinants of adherence to influenza vaccination among inner-city adults with persistent asthma. Prim Care Respir J 2007;16:229–35. pmid:17660889
- 431. Gnanasekaran SK, Finkelstein JA, Hohman K, O'Brien M, Kruskal B, Lieu TA. Parental perspectives on influenza vaccination among children with asthma. Public Health Rep 2006;121:181–188 8p. pmid:16528952
- 432. Nowalk MP, Lin CJ, Zimmerman RK, Ko F-S, Hoberman A, Zoffel L, et al. Changes in parents’ perceptions of infant influenza vaccination over two years. J Natl Med Assoc 2007;99:636–41. pmid:17595932
- 433. Avelino-Silva VI, Avelino-Silva TJ, Miraglia JL, Miyaji KT, Jacob-Filho W, Lopes MH. Campaign, counseling and compliance with influenza vaccine among older persons. Clinics (Sao Paulo) 2011;66:2031–5.
- 434. Shono A, Kondo M. Factors associated with seasonal influenza vaccine uptake among children in Japan. BMC Infect Dis 2015;15:72. pmid:25886607
- 435. Arriola CS, Mercado-Crespo MC, Rivera B, Serrano-Rodriguez R, Macklin N, Rivera A. et al. Reasons for low influenza vaccination coverage among adults in Puerto Rico, influenza season 2013–2014. Vaccine 2015;33:3829–35. pmid:26144896
- 436. Maurer J, Harris KM. Contact and communication with healthcare providers regarding influenza vaccination during the 2009–2010 H1N1 pandemic. Prev Med (Baltim) 2011;52:459–64.
- 437. Malosh R, Ohmit SE, Petrie JG, Thompson MG, Aiello AE, Monto AS. Factors associated with influenza vaccine receipt in community dwelling adults and their children. Vaccine 2014;32:1841–7. pmid:24530926
- 438. Maltezou HC, Maragos A, Halharapi T, Karagiannis I, Karageorgou K, Remoudaki H, et al. Factors influencing influenza vaccination rates among healthcare workers in Greek hospitals. J Hosp Infect 2007;66:156–9. pmid:17482717
- 439. Dedoukou X, Nikolopoulos G, Maragos A, Giannoulidou S, Maltezou H C. Attitudes towards vaccination against seasonal influenza of health-care workers in primary health-care settings in Greece. Vaccine 2010;28:5931–3. pmid:20637760
- 440. Lin CJ, Nowalk MP, Toback SL, Ambrose CS. Factors associated with in-office influenza vaccination by U.S. pediatric providers. BMC Pediatr 2013;13.
- 441. Li Y, Mukamel DB. Racial disparities in receipt of influenza and pneumococcus vaccinations among US nursing-home residents. Am J Public Health 2010;100 Suppl:S256–62. pmid:20147674
- 442. Sammon CJ, McGrogan A, Snowball J, de Vries CS. Factors associated with uptake of seasonal and pandemic influenza vaccine among clinical risk groups in the UK: an analysis using the General Practice Research Database. Vaccine 2012;30:2483–9. pmid:22133511
- 443. Norbury M, Fawkes N, Guthrie B. Impact of the GP contract on inequalities associated with influenza immunisation: A retrospective population-database analysis. Br J Gen Pract 2011;61:e379–85. pmid:21722444
- 444. Mangtani P, Breeze E, Kovats S, Ng ESW, Roberts JA, Fletcher A. Inequalities in influenza vaccine uptake among people aged over 74 years in Britain. Prev Med (Baltim) 2005;41:545–53.
- 445. Holm M V, Blank PR, Szucs TD. Trends in influenza vaccination coverage rates in Germany over five seasons from 2001 to 2006. BMC Infect Dis 2007;7:144. pmid:18070354
- 446. Santibanez TA, Santoli JM, Bridges CB, Euler GL, TA S, JM S, et al. Influenza vaccination coverage of children aged 6 to 23 months: the 2002–2003 and 2003–2004 influenza seasons. Pediatrics 2006;118:1167–75. pmid:16951012
- 447. Stockwell MS, Martinez RA, Hofstetter A, Natarajan K, Vawdrey DK. Timeliness of 2009 H1N1 vaccine coverage in a low-income pediatric and adolescent population. Vaccine 2013;31:2103–7. pmid:21458606
- 448. Balicer RD, Grotto I, Huerta M, Levian Y, Davidovitch N. Influenza vaccine refusal in Israeli young adults. Mil Med 2007;172:1093–5. pmid:17985772
- 449. Lau JS, Adams SH, Irwin CEJ, Ozer EM. Receipt of preventive health services in young adults. J Adolesc Health 2013;52:42–9. pmid:23260833
- 450. Rachiotis G, Mouchtouri VA, Kremastinou J, Gourgoulianis K, Hadjichristodoulou C. Low acceptance of vaccination against the 2009 pandemic influenza a(H1N1) among healthcare workers in Greece. Eurosurveillance 2010;15:3.
- 451. Maltezou HC, Dedoukou X, Patrinos S, Maragos A, Poufta S, Gargalianos P, et al. Determinants of intention to get vaccinated against novel (pandemic) influenza A H1N1 among health-care workers in a nationwide survey. J Infect 2010;61:252–8. pmid:20600304
- 452. Valour F, Bénet T, Chidiac C. Pandemic A(H1N1)2009 influenza vaccination in Lyon University Hospitals, France: Perception and attitudes of hospital workers. Vaccine 2013;31:592–5. pmid:23219437
- 453. La Torre G, Di Thiene D, Cadeddu C, Ricciardi W, Boccia A. Behaviours regarding preventive measures against pandemic H1N1 influenza among Italian healthcare workers, October 2009. Euro Surveill Bull Eur Sur Les Mal Transm = Eur Commun Dis Bull 2009;14.
- 454. Landelle C, Vanhems P, Saadatian-Elahi M, Voirin N. Influenza vaccination coverage among patients and healthcare workers in a university hospital during the 2006–2007 influenza season. Vaccine 2012;31:23–6. pmid:23116695
- 455. Barbadoro P, Marigliano A, Di Tondo E, Chiatti C, Di Stanislao F, D’Errico MM, et al. Determinants of influenza vaccination uptake among Italian healthcare workers. Hum Vaccin Immunother 2013;9:911–6. pmid:24064543
- 456. Barriere J, Vanjak D, Kriegel I, Otto J, Peyrade F, Esteve M, Chamorey E et al. Acceptance of the 2009 A(H1N1) influenza vaccine among hospital workers in two French cancer centers. Vaccine 2010;28:7030–4. pmid:20817011
- 457. Costantino C, Mazzucco W, Azzolini E, Baldini C, Bergomi M, Biafiore AD. et al. Influenza vaccination coverage among medical residents An Italian multicenter survey. Hum Vaccines Immunother 2014;10:1204–10.
- 458. Castilla J, Martinez-Baz I, Godoy P, Toledo D, Astray J, Garcia S, et al. Trends in influenza vaccine coverage among primary healthcare workers in Spain, 2008–2011. Prev Med (Baltim) 2013;57:206–11.
- 459. Saluja I, Theakston KD, Kaczorowski J. Influenza vaccination rate among emergency department personal: A survey of four teaching hospitals. Can J Emerg Med 2005;7:17–21.
- 460. Piccirillo B, Gaeta T. Survey on use of and attitudes toward influenza vaccination among Emergency Department staff in a New York Metropolitan Hospital. Infect Control Hosp Epidemiol 2006;27:618–22. pmid:16755483
- 461. Alhammadi A, Khalifa M, Abdulrahman H, Almuslemani E, Alhothi A, Janahi M. Attitudes and perceptions among the pediatric health care providers toward influenza vaccination in Qatar: A cross-sectional study. Vaccine 2015;33:3821–8. pmid:26144904
- 462. O’Reilly FW, Cran GW, Stevens AB. Factors affecting influenza vaccine uptake among health care workers. Occup Med (Lond) 2005;55.
- 463. Opstelten W, van Essen GA, Ballieux MJP, Goudswaard AN. Influenza immunization of Dutch general practitioners: vaccination rate and attitudes towards vaccination. Vaccine 2008;26:5918–21. pmid:18804133
- 464. Hu SS, Yang LL, Chen SH, Wang XF, Han YF, Zhang WF et al. Intention to accept pandemic H1N1 vaccine and the actual vaccination coverage in nurses at a Chinese children’s hospital. Hong Kong J Paediatr 2011;16:101–6.
- 465. King WD, Woolhandler SJ, Brown AF, Jiang L, Kevorkian K, Himmelstein DU, et al. Brief report: Influenza vaccination and health care workers in the United States. J Gen Intern Med 2006;21:181–4. pmid:16606378
- 466. Yu MC, Chou YL, Lee PL, Yang YC, Chen KT. Influenza vaccination coverage and factors affecting adherence to influenza vaccination among patients with diabetes in Taiwan. Hum Vaccines Immunother 2014;10:1028–35.
- 467. Schoefer Y, Schaberg T, Raspe H, Schaefer T. Determinants of influenza and pneumococcal vaccination in patients with chronic lung diseases. J Infect 2007;55:347–52. pmid:17681608
- 468. Althoff KN, Anastos K, Nelson KE, Celentano DD, Sharp GB, Greenblatt RM, et al. Predictors of reported influenza vaccination in HIV-infected women in the United States, 2006–2007 and 2007–2008 seasons. Prev Med (Baltim) 2010;50:223–9.
- 469. Lu P-J, Singleton JA, Rangel MC, Wortley PM, Bridges CB. Influenza vaccination trends among adults 65 years or older in the United States, 1989–2002. Arch Intern Med 2005;165:1849–56. pmid:16157828
- 470. Landi F, Onder G, Carpenter I, Garms-Homolova V, Bernabei R. Prevalence and predictors of influenza vaccination among frail, community-living elderly patients: An International Observational Study. Vaccine 2005;23:3896–901. pmid:15917110
- 471. Jimenez-Garcia R, Hernandez-Barrera V, Carrasco-Garrido P, de Andres AL, Esteban y Pena MM, de Miguel AG. Coverage and predictors of influenza vaccination among adults living in a large metropolitan area in Spain: a comparison between the immigrant and indigenous populations. Vaccine 2008;26:4218–23. pmid:18579263
- 472. Maurer J, Harris KM, Uscher-Pines L. Can routine offering of influenza vaccination in office-based settings reduce racial and ethnic disparities in adult influenza vaccination? J Gen Intern Med 2014;29:1624–30. pmid:25155638
- 473. Link MW, Ahluwalia IB, Euler GL, Bridges CB, Chu SY, Wortley PM. Racial and ethnic disparities in influenza vaccination coverage among adults during the 2004–2005 season. Am J Epidemiol 2006;163:571–578 8p. pmid:16443801
- 474. Blank PR, Schwenkglenks M, Szucs TD. Disparities in influenza vaccination coverage rates by target group in five European countries: Trends over seven consecutive seasons. Infection 2009;37:390–400. pmid:19768382
- 475. Cassidy W, Marioneaux DM, Windham AF, Manning S, Fishbein D, Horswell RL. Factors influencing acceptance of influenza vaccination given in an ED. Am J Emerg Med 2009;27:1027–33. pmid:19931746
- 476. Sanossian N, Gatto NM, Ovbiagele B. Patterns of influenza vaccination among stroke survivors. Neuroepidemiology 2009;32:165–70. pmid:19096224
- 477. Chen JY, Fox SA, Cantrell CH, Stockdale SE, Kagawa-Singer M. Health disparities and prevention: racial/ethnic barriers to flu vaccinations. J Community Health 2007;32:5–20 16p. pmid:17269310
- 478. Wu S, Yang P, Li H, Ma C, Zhang Y, Wang Q. Influenza vaccination coverage rates among adults before and after the 2009 influenza pandemic and the reasons for non-vaccination in Beijing, China: a cross-sectional study. BMC Public Health 2013;13:636. pmid:23835253
- 479. Velan B, Kaplan G, Ziv A, Boyko V, Lerner-Geva L. Major motives in non-acceptance of A/H1N1 flu vaccination: The weight of rational assessment. Vaccine 2011;29:1173–9. pmid:21167862
- 480. Sunil TS, Zottarelli LK. Student utilization of a university 2009 H1N1 vaccination clinic. Vaccine 2011;29:4687–9. pmid:21601605
- 481. Strully KW. Health care segregation and race disparities in infectious disease: the case of nursing homes and seasonal influenza vaccinations. J Health Soc Behav 2011;52:510–26. pmid:22144734
- 482. Schwarzinger M, Flicoteaux R, Cortarenoda S, Obadia Y, Moatti J-P. Low acceptability of A/H1N1 pandemic vaccination in French adult population: did public health policy fuel public dissonance? PLoS One 2010;5:e10199. pmid:20421908
- 483. Gaglia MA, Cook RL, Kraemer KL, Rothberg MB. Patient knowledge and attitudes about antiviral medication and vaccination for influenza in an internal medicine clinic. Clin Infect Dis 2007;45:1182–8. pmid:17918080
- 484. Schuller KA, Probst JC. Factors associated with influenza vaccination among US children in 2008. J Infect Public Health 2013;6:80–8. pmid:23537820
- 485. Martinez-Baz I, Aguilar I, Moran J, Albeniz E, Aldaz P, Castilla J. Factors associated with continued adherence to influenza vaccination in the elderly. Prev Med (Baltim) 2012;55:246–50.
- 486. Johnston SS, Rousculp MD, Palmer LA, Chu B-C, Mahadevia PJ, Nichol KL. Employees’ willingness to pay to prevent influenza. Am J Manag Care 2010;16:e205–14. pmid:20690787
- 487. To KW, Lee S, Chan T-O, Lee S-S. Exploring determinants of acceptance of the pandemic influenza A (H1N1) 2009 vaccination in nurses. Am J Infect Control 2010;38:623–30. pmid:20566229
- 488. Endrich MM, Blank PR, Szucs TD. Influenza vaccination uptake and socioeconomic determinants in 11 European countries. Vaccine 2009;27:4018–24. pmid:19389442
- 489. Lim PL, Tan J, Yusoff Y, Win MK, Chow A. Rates and predictors for influenza vaccine prescriptions among HIV-infected clinic patients in Singapore. Ann Acad Med Singapore 2013;42:173–7. pmid:23677211
- 490. Mouthon L, Mestre C, Berezne A, Poiraudeau S, Marchand C, Guilpain P, et al. Low influenza vaccination rate among patients with systemic sclerosis. Rheumatology (Oxford) 2010;49:600–6.
- 491. Patel R, Lawlor DA, Ebrahim S. Socio-economic position and the use of preventive health care in older British women: A cross-sectional study using data from the British Women’s Heart and Health Study cohort. Fam Pract 2007;24:7–10. pmid:17158182
- 492. Schwartz AW, Clarfield AM, Doucette JT, Valinsky L, Karpati T, Landrigan PJ et al. Disparities in pneumococcal and influenza immunization among older adults in Israel: A cross-sectional analysis of socio-demographic barriers to vaccination. Prev Med (Baltim) 2013;56:337–40.
- 493. Rossmann Beel E, Rench MA, Montesinos DP, Healy CM. Acceptability of immunization in adult contacts of infants: possibility of expanding platforms to increase adult vaccine uptake. Vaccine 2014;32:2540–5. pmid:24681227
- 494. Sibley LM, Weiner JP. An evaluation of access to health care services along the rural-urban continuum in Canada. BMC Health Serv Res 2011;11:20. pmid:21281470
- 495. Ojha RP, Stallings-Smith S, Flynn PM, Adderson EE, Offutt-Powell TN, Gaur AH. The Impact of Vaccine Concerns on Racial/Ethnic Disparities in Influenza Vaccine Uptake Among Health Care Workers. Am J Public Health 2015;105:e35–41.
- 496. Haviland AM, Elliott MN, Hambarsoomian K, Lurie N. Immunization disparities by hispanic ethnicity and language preference. Arch Intern Med 2011;171:158–65. pmid:21263106
- 497. Rangel MC, Shoenbach VJ, Weigle KA, Hogan VK, Strauss RP, Bangdiwala SI. Racial and ethnic disparities in influenza vaccination among elderly adults. J Gen Intern Med 2005;20:426–31. pmid:15963166
- 498. Hebert PL, Frick KD, Kane RL, McBean AM. The causes of racial and ethnic differences in influenza vaccination rates among elderly medicare beneficiaries. Health Serv Res 2005;40:517–37. pmid:15762905
- 499. Straits-Tröster KA, Kahwati LC, Kinsinger LS, Orelien J, Burdick MB, Yevich SJ. Racial/Ethnic Differences in Influenza Vaccination in the Veterans Affairs Healthcare System. Am J Prev Med 2006;31:375–82. pmid:17046408
- 500. Burns VE, Ring C, Carroll D. Factors influencing influenza vaccination uptake in an elderly, community-based sample. Vaccine 2005;23:3604–8. pmid:15855020
- 501. Jimenez-Garcia R, Hernandez-Barrera V, de Andres AL, Jimenez-Trujillo I, Esteban-Hernandez J, Carrasco-Garrido P. Gender influence in influenza vaccine uptake in Spain: time trends analysis (1995–2006). Vaccine 2010;28:6169–75. pmid:20659518
- 502. Shemesh AA, Rasooly I, Horowitz P, Lemberger J, Ben-Moshe Y, Kachal J, et al. Health behaviors and their determinants in multiethnic, active Israeli seniors. Arch Gerontol Geriatr 2008;47:63–77. pmid:17764762
- 503. Uscher-Pines L, Maurer J, Harris KM. Racial and ethnic disparities in uptake and location of vaccination for 2009-H1N1 and seasonal influenza. Am J Public Health 2011;101:1252–5. pmid:21566026
- 504. Shi L, Stevens GD. Vulnerability and unmet health care needs. The influence of multiple risk factors. J Gen Intern Med 2005;20:148–54. pmid:15836548
- 505. Shavers VL, Fagan P, Jones D, Klein WMP, Boyington J, Moten C, et al. The state of research on racial/ethnic discrimination in the receipt of health care. Am J Public Health 2012;102:953–66. pmid:22494002
- 506. Shui IM, Weintraub ES, Gust DA. Parents Concerned About Vaccine Safety: Differences in Race/Ethnicity and Attitudes. Am J Prev Med 2006;31:244–51. pmid:16905036
- 507. Boulware LE, Cooper LA, Ratner LE, LaVeist TA, Powe NR. Race and trust in the health care system. Public Health Rep n.d.;118:358–65.
- 508. Lewis M. Cross-cultural studies of mother-infant interaction: Description and consequence: Introduction. Hum Dev 1972.