Influenza vaccination hesitancy in five countries of South America. Confidence, complacency and convenience as determinants of immunization rates

Miguel Ángel González-Block; Emilio Gutiérrez-Calderón; Blanca Estela Pelcastre-Villafuerte; Juan Arroyo-Laguna; Yamila Comes; Pedro Crocco; Andréa Fachel-Leal; Laura Noboa; Daniela Riva-Knauth; Berenice Rodríguez-Zea; Mónica Ruoti; Elsa Sarti; Esteban Puentes-Rosas

doi:10.1371/journal.pone.0243833

Peer Review History

Original SubmissionMay 22, 2020
4 Sep 2020 Decision Letter - Holly Seale, Editor PONE-D-20-15450 Influenza vaccination hesitancy in five countries of South America. Confidence, complacency and convenience as determinants of immunization rates PLOS ONE Dear Dr. Gonzalez-Block, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. ============================== Both reviewers have provided very positive comments about your paper but have also stated that there are critical issues with the approach taken to the analysis that need to be teased out. Can I please encourage you to carefully go through these issues and update your paper accordingly ============================== Please submit your revised manuscript by Oct 19 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols We look forward to receiving your revised manuscript. Kind regards, Holly Seale Academic Editor PLOS ONE Journal requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. Please address the following: - Please ensure you have thoroughly discussed any potential limitations of this study within the Discussion section. - Please include additional information regarding the survey or questionnaire used in the study and ensure that you have provided sufficient details that others could replicate the analyses. For instance, if you developed a questionnaire as part of this study and it is not under a copyright more restrictive than CC-BY, please include a copy, in both the original language and English, as Supporting Information. In addition, please include any details concerning the validation of this tool, i.e. any pre-testing that took place. 3. Thank you for including your competing interests statement; "This project was financially supported by Sanofi Pasteur. Elsa Sarti and Esteban Puentes-Rosas are employees of Sanofi Pasteur. All other authors have no relevant conflicts of interest to report." 4. Thank you for including your ethics statement: "Brazil, Comissao Nacional de Ética em Pesquisa, 05215918.6.0000.5347. Chile: Comité de Ética de Investigación en Seres, Universidad de Chile, Facultad de Medicina, 191-2018. Paraguay: Comité de ética en Investigación, Laboratorio Central de Salud Pública, 106/2019. Peru: Comité de Ética de Investigación Prisma, CE1651.18. Uruguay: Comité de Ética en Investigación, Instituto Nacional de Salud Pública, 1580.". Please amend your current ethics statement to confirm that your named institutional review board or ethics committee specifically approved this study. Once you have amended this/these statement(s) in the Methods section of the manuscript, please add the same text to the “Ethics Statement” field of the submission form (via “Edit Submission”). For additional information about PLOS ONE ethical requirements for human subjects research, please refer to http://journals.plos.org/plosone/s/submission-guidelines#loc-human-subjects-research. 5. We note that you have indicated that data from this study are available upon request. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. In your revised cover letter, please address the following prompts: a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially identifying or sensitive patient information) and who has imposed them (e.g., an ethics committee). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent. b) If there are no restrictions, please upload the minimal anonymized data set necessary to replicate your study findings as either Supporting Information files or to a stable, public repository and provide us with the relevant URLs, DOIs, or accession numbers. Please see http://www.bmj.com/content/340/bmj.c181.long for guidelines on how to de-identify and prepare clinical data for publication. For a list of acceptable repositories, please see http://journals.plos.org/plosone/s/data-availability#loc-recommended-repositories. We will update your Data Availability statement on your behalf to reflect the information you provide. 6. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: No Reviewer #2: I Don't Know ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: No ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Overview: The paper reports the rates of vaccine hesitancy in respect to the adult influenza vaccine across five countries within South America. The confidence, complacency and convenience framework is use to assess different aspects of vaccine hesitancy. These factors are compared across risk groups, countries and to self-reported influenza vaccine uptake. General comments: The paper is well written and the topic is novel and importance to our understanding of global vaccine hesitancy. The data set clearly contains some important finding, however, the way in which you report the 3c factors and some of the statistical tests are confusing and would benefit from reworking. In this section I have outlined the 2 major issues from my perspective. Below this I have a few specific and minor comments. 1. Reporting of the 3c subscales: - As I understand it you have added the items of each of the 3c sub scales and then turned them into a number between 1 and 100 so that they are comparable. Then you have reported these as a percentage. I concerned that this makes your findings confusing, as when you report percentages it makes your finding sound like each component is a binary and the percentage is referring to how many people are e.g. complacent/not complacent (i.e. not a scale variable) - I suggest change these to a number between 1 and 10. This would make reporting clearer and distinguish these from where you report percentages of categorical variable (e.g. when you report vaccine uptake rates). If this change is made the analysis would need to be re-run, however, the conclusions would obviously remain the same. - Table 1 confuses the issue further. For the “Confidence in the vaccine” indicator you write “Resulting sum is rescaled to the interval (0,1) and expressed as %”. If I was looking at this out of context, I would assume that you had split the sample into high and low confidence and were reporting the percentage of those in one of the categories. 2. Comparison ANOVAs and Tables 3: - The use of letters to signify significance makes this table difficult to understand. It also means that the reader cannot see the level of significance or the effect size. My advice would be to check other papers in Plos One and see how they report multiple ANOVAs like this. - Type 1 errors: With the number of comparison ANOVA tests that you have conducted I am concerned with the possibility of false positives in your conclusions. At minimum a note of caution should be included in the discussion, however, I personally would reduce the alpha level throughout. This would of course change the conclusions of your analysis, especially for those results that are borderline significant, however, it would remove any spurious results. Minor comments: Line 105: Cross-section (rather than transversal) would be a more accessible, and the standard, term to use for this type of study. Line 119 -120: Please direct the reader to the section with the listed ethics details here. Line 146-147: Talking in terms of a higher and lower values and not “100 means less complacently” e.g. a higher value on complacence variable indicates a lower level of complacence. Line 169-172: As per the clarity of the 3c’s comment these would then be: “the highest normalised score for convenience (7.48, out of a possible 10)” etc. Line 173 - 182: Each comparison in this section should be accompanied with the reporting of a statistical test to demonstrate significant differences. Or point towards a table that reports all comparisons. Line 183 -185: This sentence would benefit from rephrasing. Something like “…with children and older adults reporting significantly higher levels of vaccination than the other two risk groups”, then point to a table reporting the means and statistical test. Line 202 -213: If these are correlations, please report the correlation coefficients for each. Either in the text or on the table. Table 1: - Change “Points added gradually” to “The scale was additive” - In “Complacency A. Influenza risk” construction you have the word “Idem.”, it is unclear what this means. Table 5: - Report all p values without first “0”, i.e. “<.01” - A p< .001 level of detail would be useful here. Supplemental materials: - Some parts of the questionnaire in the supplemental materials still require translating. - Data set should be made fully available Reviewer #2: This manuscript will make an important contribution to the larger literature on influenza vaccine hestiancy, particularly as it covers immunization in an understudied region. However, I think a revision is necessary to strengthen the connections between the vaccine hestiancy framework, particularly the 3 C's, and the study's research questions and conclusions. Introduction: I would have liked to see more explicit research questions. There are a lot of different factors at play here -- multiple risk groups, many different countries, several different theoretical constructs, etc. Outlining research questions may help the reader focus on the significance of this work and keep both the results and discussion sections more focused. Given the title of the paper, I was expecting more focus on the 3 C's. I find this overview of the constructs to be a bit superficial and lacking in support. Please incorporate more of the existing literature on vaccine hesitancy. Given that the conceptualizations of constructs at this stage is carried through to the development of survey measures and in analysis, this has significant bearing on the meaning of the results. Although a very different population, a recent study by Quinn et al. 2019 may be helpful. Quinn, S. C., Jamison, A. M., An, J., Hancock, G. R., & Freimuth, V. S. (2019). Measuring vaccine hesitancy, confidence, trust and flu vaccine uptake: Results of a national survey of White and African American adults. Vaccine, 37(9), 1168-1173. Ln 68: What does "mandated" mean in this context? I associate this with mandatory or required vaccination, yet the following sentences seem to suggest this is not the case. Ln 73: What would an ideal vaccination rate be? I was surprised to see rates this high. Methods: As alluded to earlier, more information is needed on item development and any reliability/validity tests that were performed. Also more information on the choice to combine all respondents into a single "high-risk" sample may be needed. What differences exist between risk groups and between countries? I need to be convinced that the measures are actually measuring what the authors claim they are. Ln 121: How does this sampling approach introduce bias? In what ways did the resulting sample differ from a more resprsentative sample? Ln 133: Since the 3 C's are so central to the arguements of this paper, it is worth describing the development of measures in greater detail in the body of the text, not just in a table. Specifically, what each indicator was designed to measure and then how well it measures it. Results: The indicators scores need to be contextualized to be meaningful. What does a convenience indicator of 74.8% mean in this context? I'm not sure what I'm supposed to take away from these results. I'm also not sure what is a "good" or "acceptable" level for any of these indicators and which are "bad" or "unacceptable" levels. Starting with how these scores correlate to vaccine behavior may be more helpful. ln 183: Why are vaccination rates so much lower than those described in the introduction? Any ideas? Ln 200: The differences in vaccination rates between Chile and Uruguay are pretty extreme. How does this impact the dataset? Did the 3 C's function the same across different countries? Discussion: With so many results to touch upon, the discussion section feels a little unfocused. Again, tying the paper more closely to the vaccine hestiancy framework and following a clear set of research questions may help tighten the focus of the paper. Some of these statments need to be further explained in much more detail. For instance, Ln 238-239. What does it mean to suggest that convenience is better than confidence and both are better than complacency? Ln 301 this paragraph feels more like a literature review than a part of the discussion. How is it tied to the study's findings? ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: Yes:** Dr Richard M Clarke Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0243833.r001
Revision 1
31 Oct 2020 Author Response Response to peer review PONE-D-20-15450 General comments Reviewer #1 The paper reports the rates of vaccine hesitancy in respect to the adult influenza vaccine across five countries within South America. The confidence, complacency and convenience framework is use to assess different aspects of vaccine hesitancy. These factors are compared across risk groups, countries and to self-reported influenza vaccine uptake. We appreciate these comments. Reviewer #2 This manuscript will make an important contribution to the larger literature on influenza vaccine hestiancy, particularly as it covers immunization in an understudied region. However, I think a revision is necessary to strengthen the connections between the vaccine hestiancy framework, particularly the 3 C's, and the study's research questions and conclusions. We appreciate these comments. Reviewer #1 The paper is well written and the topic is novel and importance to our understanding of global vaccine hesitancy. The data set clearly contains some important finding, however, the way in which you report the 3c factors and some of the statistical tests are confusing and would benefit from reworking. We appreciate these comments. Introduction Reviewer #2 I would have liked to see more explicit research questions. There are a lot of different factors at play here -- multiple risk groups, many different countries, several different theoretical constructs, etc. Outlining research questions may help the reader focus on the significance of this work and keep both the results and discussion sections more focused. We appreciate the comments and suggestions to focus on the research questions. We now propose three research questions and clarify the research objective. Given the title of the paper, I was expecting more focus on the 3 C's. I find this overview of the constructs to be a bit superficial and lacking in support. Please incorporate more of the existing literature on vaccine hesitancy. Given that the conceptualizations of constructs at this stage is carried through to the development of survey measures and in analysis, this has significant bearing on the meaning of the results. Although a very different population, a recent study by Quinn et al. 2019 may be helpful. Quinn, S. C., Jamison, A. M., An, J., Hancock, G. R., & Freimuth, V. S. (2019). Measuring vaccine hesitancy, confidence, trust and flu vaccine uptake: Results of a national survey of White and African American adults. Vaccine, 37(9), 1168-1173. We are thankful for this comment. We now provide a more in-depth overview of the 3C model based on the quantitative research reported in the literature for influenza vaccination hesitancy. Ln 68: What does "mandated" mean in this context? I associate this with mandatory or required vaccination, yet the following sentences seem to suggest this is not the case. We substitued "mandated" with "recommended and publicily financed for" Ln 73: What would an ideal vaccination rate be? I was surprised to see rates this high. We now cite WHO recommendations of reachibng desirable vaccination rates of 90% for 2020. Methods Reviewer #1 1. Reporting of the 3c subscales: - As I understand it you have added the items of each of the 3c sub scales and then turned them into a number between 1 and 100 so that they are comparable. Then you have reported these as a percentage. I concerned that this makes your findings confusing, as when you report percentages it makes your finding sound like each component is a binary and the percentage is referring to how many people are e.g. complacent/not complacent (i.e. not a scale variable) I suggest change these to a number between 1 and 10. This would make reporting clearer and distinguish these from where you report percentages of categorical variable (e.g. when you report vaccine uptake rates). If this change is made the analysis would need to be re-run, however, the conclusions would obviously remain the same. We have rescaled the variables as suggested to report our results more clearly. Table 1 confuses the issue further. For the “Confidence in the vaccine” indicator you write “Resulting sum is rescaled to the interval (0,1) and expressed as %”. If I was looking at this out of context, I would assume that you had split the sample into high and low confidence and were reporting the percentage of those in one of the categories. Text in the table is now restated in terms of the new categorization. 2. Comparison ANOVAs and Table 3: The use of letters to signify significance makes this table difficult to understand. It also means that the reader cannot see the level of significance or the effect size. My advice would be to check other papers in Plos One and see how they report multiple ANOVAs like this. We are maintaining the use of letters to represent significance as this device allows us to compare significant differences between pairs of countries. However, we now specify the alpha level in the table footer to the level <.001 Type 1 errors: With the number of comparison ANOVA tests that you have conducted I am concerned with the possibility of false positives in your conclusions. At minimum a note of caution should be included in the discussion, however, I personally would reduce the alpha level throughout. This would of course change the conclusions of your analysis, especially for those results that are borderline significant, however, it would remove any spurious results. We have reduced the alpha level to <.001. Most results were significant at this level, except when noted. Reviewer #2 As alluded to earlier, more information is needed on item development and any reliability/validity tests that were performed. Ln 133: Since the 3 C's are so central to the arguements of this paper, it is worth describing the development of measures in greater detail in the body of the text, not just in a table. Specifically, what each indicator was designed to measure and then how well it measures it. We now report on the procedure used for the development of indicators and cite the relevant references. Also more information on the choice to combine all respondents into a single "high-risk" sample may be needed. What differences exist between risk groups and between countries? I need to be convinced that the measures are actually measuring what the authors claim they are. Reflecting on the pertinence of combining all respondents ino a single group, we coma to the conclusion that it is not meaningful and have therefore deleted in tables and text reference to these aggregate values. We focus now the analysis on differences for each indicator across risk groups and countries. Ln 121: How does this sampling approach introduce bias? In what ways did the resulting sample differ from a more resprsentative sample? We now discuss in the limitation of the study the possible biases of our sampling strategy with respect to service utilization. Results Reviewer #2 The indicators scores need to be contextualized to be meaningful. What does a convenience indicator of 74.8% mean in this context? I'm not sure what I'm supposed to take away from these results. I'm also not sure what is a "good" or "acceptable" level for any of these indicators and which are "bad" or "unacceptable" levels. Starting with how these scores correlate to vaccine behavior may be more helpful. We have revised the interpretation of the 3C indicators to avoid comparison across them, and limit comparison within each indicator across risk groups and countries. However, we consider it reasonable to compare indicators across each other with respect to their association with vaccination status. ln 183: Why are vaccination rates so much lower than those described in the introduction? Any ideas? We take up in the Discussion the differences between reported national vaccionation rates and our results. Ln 200: The differences in vaccination rates between Chile and Uruguay are pretty extreme. How does this impact the dataset? Did the 3 C's function the same across different countries? As stated in the Introduction, countries were chosen across the continuum of vaccionation coverage. We discuss differenvrd in the 3C and reported vaccination rates across countries in lines 622 to 636. Discussion Reviewer #2 With so many results to touch upon, the discussion section feels a little unfocused. Again, tying the paper more closely to the vaccine hestiancy framework and following a clear set of research questions may help tighten the focus of the paper. We have formulated three research questions and refocused the discussion accordingly. Some of these statments need to be further explained in much more detail. For instance, Ln 238-239. What does it mean to suggest that convenience is better than confidence and both are better than complacency? Following from our response to reviewer 2' s comment for the Results section above, we now avoid comparing across the 3C indicators, except when discussing their association wih vaccination status. We have therefore removed the disciussion of comparisons across indicators. Ln 301 this paragraph feels more like a literature review than a part of the discussion. How is it tied to the study's findings? We now integrate the two references in this paragrpah as similar evidence that is similar to our study on the importance of confidence and complacency. Minor comments: Reviewer #1 Line 105: Cross-section (rather than transversal) would be a more accessible, and the standard, term to use for this type of study. We have changed the wording Line 119 -120: Please direct the reader to the section with the listed ethics details here. We have directed the reader to the ethics details as suggested Line 146-147: Talking in terms of a higher and lower values and not “100 means less complacently” e.g. a higher value on complacence variable indicates a lower level of complacence. We have modified the wording accordingly Line 169-172: As per the clarity of the 3c’s comment these would then be: “the highest normalised score for convenience (7.48, out of a possible 10)” etc. We have modified the wording accordingly Line 173 - 182: Each comparison in this section should be accompanied with the reporting of a statistical test to demonstrate significant differences. Or point towards a table that reports all comparisons. We are now stating that results are at the p<.001 unless otherwise stated. We are also pointing to table 3 for further details. Line 183 -185: This sentence would benefit from rephrasing. Something like “…with children and older adults reporting significantly higher levels of vaccination than the other two risk groups”, then point to a table reporting the means and statistical test. We have modified the wording following the suggestion. Line 202 -213: If these are correlations, please report the correlation coefficients for each. Either in the text or on the table. No, these are not correlations. The analysis is based on analysis of variance models. Table 1: Change “Points added gradually” to “The scale was additive” We have modified the wording In “Complacency A. Influenza risk” construction you have the word “Idem.”, it is unclear what this means. We have modifided the wording, now stating "Same as above". Table 5: Report all p values without first “0”, i.e. “<.01” We have modified deleting the 0. A p< .001 level of detail would be useful here. We are now reporting at the <.001 level. Supplemental materials: Some parts of the questionnaire in the supplemental materials still require translating. We have completed the translation Data set should be made fully available We are now making the dataset available. Attachments Attachment Submitted filename: Response to peer review PONE.pdf https://doi.org/10.1371/journal.pone.0243833.r002
27 Nov 2020 Decision Letter - Holly Seale, Editor Influenza vaccination hesitancy in five countries of South America. Confidence, complacency and convenience as determinants of immunization rates PONE-D-20-15450R1 Dear Dr. Gonzalez-Block, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Holly Seale Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: All my previous comments appear to have been addressed and I am happy for to recommend the article for publication. ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: Yes:** Dr Richard M Clarke https://doi.org/10.1371/journal.pone.0243833.r003
Formally Accepted
2 Dec 2020 Acceptance Letter - Holly Seale, Editor PONE-D-20-15450R1 Influenza vaccination hesitancy in five countries of South America. Confidence, complacency and convenience as determinants of immunization rates Dear Dr. González-Block: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Holly Seale Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0243833.r004

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .