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Characteristics and burden of acute COVID-19 and long-COVID: Demographic, physical, mental health, and economic perspectives

  • Manuel Leitner,

    Roles Formal analysis, Methodology, Validation, Visualization, Writing – original draft

    Affiliation Division of Neurogeriatrics, Department of Neurology, Medical University of Graz, Graz, Austria

  • Gloria Pötz,

    Roles Conceptualization, Data curation, Investigation, Methodology, Project administration, Visualization, Writing – review & editing

    Affiliation digitAAL Life GmbH, Graz, Austria

  • Martin Berger,

    Roles Conceptualization, Data curation, Investigation, Methodology, Project administration, Visualization, Writing – review & editing

    Affiliation Division of Neurogeriatrics, Department of Neurology, Medical University of Graz, Graz, Austria

  • Maria Fellner,

    Roles Conceptualization, Data curation, Investigation, Methodology, Project administration, Resources, Supervision, Visualization, Writing – review & editing

    Affiliation digitAAL Life GmbH, Graz, Austria

  • Stephan Spat,

    Roles Conceptualization, Data curation, Investigation, Methodology, Project administration, Visualization, Writing – review & editing

    Affiliation digitAAL Life GmbH, Graz, Austria

  • Marisa Koini

    Roles Conceptualization, Data curation, Investigation, Methodology, Project administration, Resources, Supervision, Visualization, Writing – review & editing

    Affiliation Division of Neurogeriatrics, Department of Neurology, Medical University of Graz, Graz, Austria



COVID-19 infection and its associated consequence, known as long-COVID, lead to a significant burden on the global healthcare system and limitations in people’s personal and work lives. This study aims to provide further insight into the impact of acute and ongoing COVID-19 symptoms and investigates the role of patients’ gender and vaccination status.


416 individuals (73.9% female) between the ages of 16 and 80 years (M = 44.18, SD = 12.90) with self-reported symptoms of long-COVID participated in an online survey conducted between March and May 2022.


6.0%, 74.3%, and 19.7% of all respondents reported having had an asymptomatic, mild, or severe acute illness, respectively. Out of all participants, 7.8% required hospitalization. The most prevalent symptoms during the acute infection (Mdn = 23.50 symptoms, IQR = 13–39) included fatigue, exhaustion, cough, brain fog, and memory problems. The median long-COVID disease duration was 12.10 months (IQR = 2.8–17.4). Among 64 inquired long-COVID symptoms (Mdn = 17.00 symptoms, IQR = 9–27), participants reported fatigue, exhaustion, memory problems, brain fog, and dyspnea as the most common ongoing symptoms, which were generally experienced as fluctuating and deteriorating after physical or cognitive activity. Common consequences of long-COVID included financial losses (40.5%), changes in the participants’ profession (41.0%), stress resistance (87.5%), sexual life (38.1%), and mood (72.1%), as well as breathing difficulties (41.3%), or an increased drug intake (e.g., medicine, alcohol; 44.6%). In addition, vaccinated individuals exhibited a shorter acute illness duration and an earlier onset of long-COVID symptoms. In general, women reported more long-COVID symptoms than men.


Long-COVID represents a heterogeneous disease and impacts multiple life aspects of those affected. Tailored rehabilitation programs targeting the plurality of physical and mental symptoms are needed.


Since the World Health Organization (WHO) declared the coronavirus disease a global pandemic in March 2020, over 770 million confirmed cases [1] of COVID-19 have been recorded so far (11/2023). Although roughly 80% suffer a mild or moderate illness [2], some are at risk of a severe disease course, requiring intensive medical attention [3]. During the acute phase of an infection, symptoms typically encompass, but are not limited to, fever, cough, fatigue, dyspnea, or muscle aches [4, 5].

As the rate of infections remains elevated, the number of patients with persisting symptoms is increasing as well, leading to a significant amount of sickness rates and ongoing health challenges. Although there is a tremendous amount of heterogeneity in the definition of long-COVID in interventional studies [6], health experts defined the permanence of symptoms beyond four weeks after an initial infection subsided as long-COVID [7, 8]. Long-COVID includes both ongoing symptomatic COVID-19 (4–12 weeks) and the post-COVID-19 syndrome (+12 weeks) [9]. As persisting/ongoing symptoms such as cognitive impairment or fatigue can arise regardless of the initial illness severity [7, 1012], a considerable number of individuals might develop long-COVID symptoms, especially if the virus continues to spread rapidly. These health issues could especially affect women and unvaccinated individuals, as research suggests a higher risk of long-COVID for women [7, 13, 14] and those without a COVID-19 vaccination [15]. Among various other risk factors, also a heightened body mass index [16] and a higher age [17] might increase the risk of developing long-COVID.

In general, the most common long-COVID symptoms include fatigue, chest pain, dyspnea, and cough [18], but also cognitive symptoms such as memory problems and brain fog are reported frequently [11]. As those symptoms may persist for months, the outbreak of the coronavirus disease has led to significant changes in the occupational [19] and personal lives of those affected. Individuals may need to consider reducing their working hours or are completely incapable of work [11, 20]. Others might be affected by psychological challenges, such as an increased level of depression, anxiety, anhedonia, or stress [2123]. In addition, changes in peoples’ sex life were observed [7], such as a high prevalence of erectile dysfunction [24]. Finally, many also experience cognitive/mental limitations, such as global cognitive dysfunction [20], brain fog [25], attention disorders [22, 26] or memory problems [27].

Despite extensive examination of the diverse domains affected by individuals suffering from long-COVID, detailed information about the variety of symptoms and negative impact on work-life (e.g., changes in a person’s profession), private-life (e.g., stress, mood, need for assistance, and sex life), and cognition is scarce [11, 28].

Hence, there is an urgent need to investigate this complex medical condition and raise awareness regarding the ongoing effects of the COVID-19 pandemic. The current study aims at (a) describing the disease course, duration, and self-reported severity of participants’ acute COVID-19 infection, (b) characterizing the frequency and burden of acute and ongoing symptoms, (c) analyzing the impact of those symptoms on a variety of domains, including work life, financial losses, drug/medication intake, stress, mood, breathing, and sexuality, (d) investigating differences between vaccinated/unvaccinated individuals as well as between male and female respondents, (e) and analyzing the relationship between selected risk factors (e.g., BMI) and long-COVID symptoms.

Materials and methods

Participants and recruitment

This study represents a cross-sectional online survey available from March 29th to May 3rd, 2022. All questions were presented in German. The study was approved by the ethics committee of the Medical University of Graz (34–166 ex 21/22). Informed consent was obtained by accepting an online data privacy statement, and participants were informed about the objective and duration of the study. All responses were anonymous and participants were free to withdraw from the study at any time, without providing reasons and without any negative consequences. Participants were recruited through social media advertisements, press releases, and information folders distributed in rehabilitation clinics. The online platform “LimeSurvey” was used to collect the data. ML, BM, GP and MK are specially trained in generating (online) questionnaires. Before and during the generation of the questionnaire, authors interviewed long-COVID patients, experts working with COVID patients (such as general doctors, neurologists, and nurse specialists), family members and the founder of a support group for long-COVID. Based on this information, we created the questionnaire used in this study and gave it to three long-COVID patients who evaluated it regarding its comprehensibility and goal-directedness. Afterwards, the questionnaire was adapted based on the feedback of the patients.

An a priori sample size calculation was conducted to determine the appropriate sample size for this study. The calculation was performed using the program G*Power (Version 3.1) and was based on an alpha level of 0.05, a statistical power of 0.80 and an anticipated medium effect size. The calculation indicated that a minimum of 159 individuals is required to detect the anticipated effects for all inferential statistical analyses.

The study sample comprised 416 individuals (73.9% female) between the ages of 16 and 80 years (M = 44.18, SD = 12.90) with a median active disease duration of 11–15 days (IQR: 6–10–16–20 days) and a median long-COVID disease duration of about 12 months (IQR: 2.77–17.36). As it was not mandatory to answer all questions provided, the sample size varies among questions. The majority reported being from Austria (91.1%), holding a university degree (26.3%), and reported working as an employee (70.2%). Detailed demographic information is provided in Table 1. Additionally, information regarding pre-existing health conditions was gathered and depicted in Table 2. There were no exclusion criteria in this study. However, the survey only targeted individuals with self-reported symptoms of long-COVID. Those with implausible values (e.g., year of birth “2022”) were excluded from the analyses.


The online survey assessed several domains, including demographic characteristics, pre-existing health conditions, duration of the initial COVID-19 illness, course of the disease, hospitalization rates, frequency and burden of acute (“which symptoms did you experience during the acute COVID-19 infection and how burdensome were these symptoms for you?”) and ongoing/long-COVID (“what long-COVID symptoms do you experience and how burdensome are these symptoms for you?”) symptoms (assessed utilizing a Likert Scale ranging from 1 to 5), the onset and relation between long-COVID symptoms, medical examinations, utilization of long-COVID therapies, changes in long-COVID symptoms, changes in breathing, stress, or mood, need for support, substance abuse, sexual alterations, financial changes and changes in the participants’ occupation due to long-COVID, information about the participants’ vaccination status and administered vaccines, training opportunities, and training motivation. Data was collected using single-choice and multiple-choice questions, which could be answered on a computer, mobile phone, or tablet. Participants had the option to provide additional information to specific questions by using text fields in the survey. The online survey took approximately 10 to 15 minutes to be completed.

Statistical analysis

The data were analyzed using the statistics software SPSS (Version 29.0). We used descriptive statistics to describe the data. Chi-square or Fisher’s exact tests were computed to examine the relationship between categorical variables. Non-parametric tests (e.g., Mann-Whitney-U, Kruskal-Wallis) were applied to ordinal data or skewed continuous variables. Finally, univariate comparisons for continuous variables were performed using analyses of variance (ANOVAs) and corresponding post-hoc tests. We computed Spearman correlation coefficients to analyze relations between not normally distributed continuous or ordinal scaled variables, otherwise Pearson correlations were performed. A significance level of α = .05 was used. Effect sizes (e.g., Cohen’s d, ηp2, φc, OR, r) were calculated and specified in the corresponding analyses. All research data used in this study can be accessed in the S1 File (


Acute COVID-19 infection: Symptoms and burden

Individuals with self-reported symptoms of long-COVID and stating to have had a COVID-19 infection between February 2020 and May 2022 were included in the subsequent analyses. A graphic illustration of the infection frequency as a function of time is depicted in Fig 1. The duration of participants’ acute illness was positively skewed with a median of 11–15 days (IQR: 6–10–16–20 days) (Fig 2). Out of 299 respondents, the majority (74.3%) reported having had a mild course of disease (n = 222), while 6.0% (n = 18) had an asymptomatic or severe (19.7%, n = 59) disease course, respectively. Detailed information is presented in Table 3. Moreover, 7.8% stated they were admitted to the hospital. Of those dependent on hospital care due to the severity of their symptoms during the acute illness (n = 23), 60.9% were treated on a COVID-19 ward, while 17.4% were admitted to an ICU or did not further specify their hospital admission (21.7%). The median length of hospitalization was 0–10 days (IQR: 0–10–21–30 days) and only one respondent reported a hospitalization duration exceeding one month (Table 4).

Fig 1. Infection frequency of survey respondents as a function of time.

Fig 2. Duration of participants’ acute COVID-19 illness.

d = days, m = months.

Table 3. Detailed information about the duration and severity of participants’ acute infection.

Table 4. Duration of hospitalization during the acute illness.

The participants experienced a median number of 23.5 different symptoms (IQR: 13–39 symptoms) during the acute phase of their illness. The most common initial symptoms included fatigue (93.4%), tiredness/exhaustion (84.4%), dry cough (76.2%), cognitive dysfunction (e.g., brain fog; 75.5%), poor memory (75.2%), a runny nose (73.8%), headache or headache-associated symptoms (72.5%), loss of appetite (72.5%), fever (72.2%), sweating or chills (71.9%), muscle aches (71.9%), and dyspnea (71.2%). A comprehensive list of symptoms can be found in Fig 3 and S1 Table.

Fig 3. Percent of COVID-19 symptoms during the acute phase of the illness.

The subjective burden of those symptoms during the acute and ongoing phase was assessed using a 5-point Likert Scale (1 = very mild to 5 = very strong). Exhaustion (M = 4.13, SD = 0.94), an altered sense of taste and smell (M = 3.97, SD = 1.31), fatigue (M = 3.96, SD = 1.02), discomfort after physical exertion (M = 3.82, SD = 1.04), headache or headache-associated symptoms (M = 3.76, SD = 1.18), and dyspnea (M = 3.59, SD = 1.22) were reported to be the most significant burdens during the acute illness (S1 Table). In general, respondents experienced a very mild (26.4%) or mild (15.4%) burden caused by their symptoms, while the majority reported a moderate (22.1%), strong (20.0%), or very strong (16.1%) burden, respectively.

Long-COVID: Symptoms and burden

A median number of 17.0 (IQR: 9–27) symptoms that persisted or were developed after the acute COVID-19 infection were reported. The most prevalent were fatigue (97.4%), exhaustion (83.8%), poor memory (82.7%), cognitive dysfunction (e.g., brain fog; 77.1%), dyspnea (70.5%), discomfort after physical exertion (63.8%), chest discomfort (62.4%), dizziness (62.0%), headache or headache-associated symptoms (59.0%), insomnia (56.1%), breathing difficulties (55.4%), and muscle aches (49.8%). Detailed information about the frequency and burden of all long-COVID symptoms is depicted in S2 Table and Fig 4.

Fig 4. Percent of ongoing or newly developed symptoms (long-COVID symptoms).

The most significant burden was found to be associated with symptoms such as fatigue (M = 4.12, SD = 0.99), exhaustion (M = 4.03, SD = 0.96), discomfort after physical exertion (M = 3.92, SD = 0.94), sleep alterations (M = 3.44, SD = 1.16), an altered sense of taste and smell (M = 3.44, SD = 1.46), and cognitive dysfunction (e.g., brain fog; M = 3.43, SD = 1.21) (S2 Table). In general, participants experienced a very mild (18.6%), mild (19.4%), moderate (26.1%), strong (20.2%) or very strong (15.7%) burden by their long-COVID symptoms, respectively.

About half of the study participants (49.8%, n = 132/265) reported the onset of their long-COVID symptoms within the initial two weeks after the acute infection. 18.9% (n = 50) stated that their symptoms emerged between the third- and fourth-week post-infection, while 15.8% (n = 42) of the respondents experienced the appearance of ongoing symptoms two- or three months post-infection. A further 15.5% (n = 41) reported ongoing symptoms immediately after their infection, after vaccination, or later than three months post-acute infection.

Extramural examination of long-COVID symptoms

62.3% (n = 162/260) underwent medical examinations to clarify their symptoms. These evaluations encompassed pulmonary function tests (72.8%, n = 118), X-rays (53.1%, n = 86), neurological assessments (41.4%, n = 67), MRI scans (38.3%, n = 62), CT scans (35.2%, n = 57), neuropsychiatric evaluations (25.9%, n = 42), and other tests such as ECG (electrocardiogram) or blood tests (18.5%, n = 30). A long-COVID outpatient clinic was visited by 17.7% (n = 46/260) of all respondents. In addition, 21.9% reported having visited a specialized long-COVID rehabilitation clinic due to their long-COVID symptoms. Numerous study respondents (n = 152) further reported connections between their symptoms, for instance, a simultaneous occurrence of anxiety and dyspnea, exhaustion and concentration difficulties, memory problems and headache or between physical exhaustion and cognitive symptoms (e.g., concentration difficulties, or trouble with finding the correct words).

Alteration of long-COVID symptoms

We further asked all participants about alterations in their long-COVID symptoms by using several multiple-response questions. The majority reported that their symptoms got worse after physical (70.2%, n = 186) or mental (52.1%, n = 138) activity, while 53.6% (n = 142) described them as fluctuating. However, some even reported an improvement in their symptoms after physical (8.3%, n = 22) or mental (4.5%, n = 12) activity. Moreover, 26.0% (n = 69) experienced an overall improvement in their symptoms, while 7.9% (n = 21) reported a substantial deterioration of their long-COVID symptoms. A further 28.3% (n = 75) described their symptoms as unchanged since their onset. The findings are summarized in Table 5.

To alleviate the negative impact of long-COVID, participants reported engaging in movement (59.0%, n = 138), breathing (53.4%, n = 125), and cognitive exercises (36.8%, n = 86). Nonetheless, about a quarter (27.4%, n = 64) stated having not attempted any exercises yet, although many consider that breathing (65.4%), movement (80.4%), and cognitive exercises (72.1%) could potentially mitigate their symptoms. The participants mentioned a possible enhancement of their overall health as a crucial motivational factor for starting a training program.

Impact of long-COVID on participant’s professional life

A total of 41.0% (n = 133 of 324 respondents) experienced work-related changes since the onset of their long-COVID symptoms. Of those, 9.0% stated to now be unable to work, 23.3% had to reduce working hours, 57.9% went on sick leave, and 25.6% reported other changes in their work routine, such as termination or the requirement for rehabilitation. The median number of work-related sick days was 16 days (IQR: 10–42 days). In addition, substantial financial losses were reported by 40.5% of all study participants.

Impact of long-COVID on participants’ physical and mental health

Regarding breathing difficulties among the survey participants (n = 242), 58.7% reported having complete control over their breathing during the day, while the remaining 41.3% stated that control over their breathing is situational. A few (1.1%, n = 3) even require oxygen therapy at home. Further, some (23.3%) depend on help from relatives or external organizations in order to perform daily tasks such as cooking, cleaning, childcare responsibilities, or lifting heavy loads.

Additionally, nearly half of all respondents (44.6%, n = 116/260) reported a significant increase in substance or medication intake (e.g., alcohol, medication, drugs), and more than a third experienced noticeable changes in their sexual life (e.g., loss of libido; 38.1%, n = 88/231). One factor driving these changes was fatigue, as those who experienced substantial changes in their sexual life (MR = 130.80, Mdn = 5.00) experienced a higher burden of fatigue as compared to those who did not report any sexual alterations (MR = 99.29, Mdn = 4.00) (U = 4188.00, z = -3.82, p < .001, r = -0.26).

Finally, the impact of long-COVID extends beyond physical limitations and encompasses substantial psychological alterations as well. 87.5% (n = 231/264) reported a modification in their stress load capacity, as most of these individuals experienced a considerable deterioration (97.0%). Further, mood changes were reported in about 72.1% (n = 189/262). Of those, the majority (91.5%) experienced a worsening of their mood since their COVID-19 infection and the associated long-COVID symptoms.

Vaccination status

134 out of 296 individuals (45.3%) stated to have received a COVID-19 vaccine before their SARS-CoV-2 infection. However, as many study participants got infected prior to the public availability of COVID-19 vaccines in Austria, we further assessed their vaccination status after their infection (when they completed the online survey). 85.2% (n = 138/162) of those unvaccinated at the time of their infection got vaccinated after their illness, while 14.8% (n = 24) declined to receive a COVID-19 vaccine up to the point of our data collection. The most common vaccine at the first vaccination (n = 111) was Comirnaty (BioNTech Pfizer; 60.4%, n = 67), followed by Vaxzevria (AstraZeneca; 33.3%, n = 37) and Spikevax (Moderna; 6.3%, n = 7). A comparable pattern was observable for participants’ second and third vaccination.

Differences between vaccinated and unvaccinated individuals

Participants who had received at least one dose of the COVID-19 vaccine at the time of their infection (n = 128) experienced a significantly shorter acute illness duration (MR = 113.72, Mdn = 6–10 days) compared to those who were not vaccinated (n = 156) prior to their infection (MR = 166.11, Mdn = 11–15 days; U = 6300.50, z = -5.52, p < .001, r = -.33). However, there was no difference between the groups in terms of their self-reported disease course/illness severity (n = 289, χ2(2) = 3.04, p = .219, φc = .10) or hospitalization rates (n = 191, χ2(1) = 0.01, p = .904, OR = 1.05, 95% CI (0.45, 2.49), φc = .01).

With respect to work absence, no differences in sick leave days were found between vaccinated (n = 115) and unvaccinated (n = 127) individuals (U = 6364.00, z = -1.73, p = .084, r = -.11). Furthermore, both groups (n = 257) did not differ in the frequency of needing support from family, friends, or caregivers (χ2(1) = 0.50, p = .479, OR = 1.24, 95% CI (0.69, 2.23), φc = .04). However, those unvaccinated at the time of their COVID-19 infection more frequently reported having visited a rehabilitation clinic than vaccinated participants (χ2(1) = 36.11, p < .001, OR = 14.06, 95% CI (4.90, 40.36), φc = .37).

Also, the onset of long COVID symptoms (time until new symptoms emerged after the infection) was found to be significantly earlier in vaccinated (n = 99, MR = 91.85, Mdn = after 1–2 weeks) than in unvaccinated (n = 122, MR = 126.54, Mdn = after 3–4 weeks) participants (U = 4143.00, z = -4.52, p < .001, r = -.30). Finally, there was no significant difference between the groups regarding the number of their acute (n = 295, U = 10168.50, z = -0.85, p = .396, r = -.05) or ongoing COVID-19 symptoms (n = 265, U = 8055.50, z = -0.86, p = .388, r = -.05).

Differences between male and female respondents

We did not find any statistically significant differences between men and women in the duration of their acute COVID-19 infection (n = 284, U = 7586.50, z = -0.64, p = .521, r = -.04), self-reported disease course/illness severity (n = 289, χ2(2) = 0.60, p = .740, φc = .05), or hospitalization rates (n = 291, χ2(1) = 3.72, p = .054, OR = 2.30, 95% CI (0.86, 5.98), φc = .11). However, the hospitalization analyses indicated a possible trend towards higher hospitalization rates for men (13.0%) compared to women (6.1%).

Further, no differences in the number of sick leave days (n = 244, U = 4821.00, z = -1.72, p = .086, r = -.11), the frequency of needing support from family, friends, or caregivers (χ2(1) = 1.20, p = .273, OR = 1.47, 95% CI (0.74, 2.91), φc = .07), the frequency of having visited a rehabilitation clinic (χ2(1) = 0.09, p = .767, OR = 0.91, 95% CI (0.47, 1.75), φc = .02), or the onset of long-COVID symptoms (n = 220, U = 5336.00, z = 1.74, p = .081, r = .12) were observed.

Concerning the frequency of symptoms during the acute phase of the illness, no significant difference was observed between men and women as well (U = 8247.50, z = -0.34, p = .731, r = —.02). However, in general, women (MR = 141.39, Mdn = 18 symptoms) reported significantly more ongoing COVID-19 (long-COVID) symptoms compared to men (MR = 110.98, Mdn = 13 symptoms) (U = 5242.50, z = -2.83, p = .005, r = -.17).

Possible risk factors associated with acute COVID-19 and long-COVID symptoms

Next, we were interested in possible risk factors (BMI, age, and hypertension) associated with participants’ acute infection and ongoing symptoms. A higher BMI (M = 26.19, SD = 6.73) was associated with a longer duration of illness during the initial COVID-19 infection (rs = .13, p = .025).

Further analyses confirmed that individuals with different self-reported disease courses (asymptomatic (n = 17), mild (n = 210), severe (n = 56)), on average, differed in their body mass index (F(2, 280) = 5.50, p = .005, ηp2 = .038). We found significant differences between individuals with a mild (M = 25.46 kg/m2, SD = 6.55) and severe (M = 28.71 kg/m2, SD = 7.29) illness (Mdiff = 3.25 kg/m2, p = .004), while no differences to asymptomatic individuals (M = 27.15 kg/m2, SD = 5.37) were observable (asymptomatic vs. mild: p = .675; asymptomatic vs. severe: p = .778).

In addition, no age differences between individuals with different disease courses (asymptomatic (n = 17), mild (n = 202), or severe (n = 57)) were found in this data (F(2, 273) = 1.90, p = .151, ηp2 = .014), but our analyses revealed a positive relationship between age (M = 44.69, SD = 12.81) and participants’ illness duration during their acute infection (rs = .23, p < .001). However, age was not associated with the frequency of acute COVID-19 symptoms (r = .02, p = .713) and long-COVID symptoms (r = .03, p = .627).

Among 340 participants that made a statement about their blood pressure, 8.8% (n = 30) suffered from hypertension. Participants with heightened blood pressure (MR = 159.25, Mdn = 11–15 days) did not statistically differ in the duration of their acute illness from normotensive participants at the time of completing the survey (MR = 143.47, Mdn = 11–15 days) (n = 289, U = 4053.00, z = 0.98, p = .327, r = .06). In addition, no statistically significant differences between those with and without hypertension were found regarding their self-reported illness severity (asymptomatic, mild, severe; n = 294, χ2(2) = 5.59, p = .061, φc = .14), the frequency of symptoms during their acute illness (U = 3959.00, z = -1.35, p = .178, r = -.07) or ongoing symptoms (U = 4329.50, z = -0.63, p = .531, r = -.03), and the time until the occurrence of long-COVID symptoms (U = 2274.00, z = -1.09, p = .275, r = -.07).


The findings of the present online study offer valuable insight into the various domains impacted by individuals suffering from long-COVID. Symptoms such as fatigue, exhaustion, and considerable cognitive deficits (e.g., brain fog or memory problems) were predominant in both the acute and ongoing phases of their illness. This clinical presentation is consistent with other studies, indicating that long-COVID symptoms affect multiple organ systems, with cognitive dysfunction and fatigue being among the most frequent ongoing symptoms [20]. Although those symptoms were already reported in other studies [11, 20], our findings suggest that they were experienced as a significant burden for those affected, which might lead to serious mood disorders such as depression or anxiety [29]. Thus, highlighting the burden and impact of long-COVID and focusing on tailored rehabilitation opportunities represents a significant challenge for future research on this topic. We could further confirm a shorter acute illness duration and an earlier onset of long-COVID symptoms in vaccinated compared to unvaccinated individuals, as well as a higher number of long-COVID symptoms in women than in men. The key findings of the present study are summarized in the following section and compared to the current state of knowledge.

Acute COVID-19 illness

Consistent with one of the earliest studies investigating the course of a coronavirus infection [2], reporting about 81% of mild and 19% of severe/critical cases, most participants in the present study stated to have experienced a mild (74.3%), severe (19.7%) or asymptomatic (6.0%) infection. In line with Menni et al. [30], the acute illness of most individuals did not exceed about two weeks. Symptoms affecting the respiratory tract (e.g., cough, dyspnea, chest tightness) as well as fatigue/exhaustion, fever, headache, or cognitive dysfunction were present as typical signs of an acute COVID-19 infection [11, 31, 32]. Our results further suggest that both a higher body mass index and a higher age are associated with a longer-lasting illness during the acute infection. A higher BMI, on average, was further present in those with a more significant illness severity [33, 34]. In addition, diverging illness characteristics of vaccinated (45.3%) and unvaccinated (54.7%) individuals (at the time of their infection) were present, as not being vaccinated was associated with a longer-lasting acute infection. Finally, although belonging to the male sex was found to be associated with an increased risk of hospitalization in previous studies [35], no significant gender differences in hospitalization rates were present in the current study. Nonetheless, we found indications that men were hospitalized about twice as often as women (13.0% vs. 6.1%).


In the majority (49.8%), ongoing or newly developed symptoms emerged already in the first two weeks post-infection. Common symptoms included fatigue, exhaustion, memory problems, cognitive dysfunction, and dyspnea. Consequently, numerous participants reported an adverse impact regarding their profession (41.0%), financial losses (40.5%), and changes in their ability to cope with stress (87.5%). Those affected encountered changes in their work life such as sick leave, loss of income, and reduced working hours or were even incapable of work which also aligns with prior literature [11, 20]. Ziauddeen et al., for instance, reported a loss of income in 37.6% of all study participants [11], comparable to a high number of 40.5% of participants in the current study.

Furthermore, long-COVID symptoms such as cognitive dysfunction or brain fog [20, 36, 37] might interfere with demands in the work and private life of those affected, as those symptoms were often described as fluctuating and deteriorating after physical or cognitive activity [11]. Consequently, reducing working hours has been a common outcome for those suffering from long-COVID [11, 20]. A gradual reintegration into the labor market as well as adjusted working hours might be advisable to prevent prolonged sick leave or early retirement.

It is concerning to note that a considerable number of participants in the current study experienced changes in their mood (72.1%), had problems with their breathing control (41.3%), were dependent on help from organizations or relatives (23.3%) or suffered from changes in their sexual life (38.1%). Alterations in the sexual life (e.g., erectile dysfunction) of patients living with long-COVID had also been reported in previous studies [24], which might lead to significant distress. Psychological distress and depressive symptoms were found to be prevalent in more than 25% of individuals three months after the acute phase of infection [38], suggesting that the risk of mood disorders such as depression or anxiety in COVID-19 survivors is high [39]. Comprehensive mental health care and clinical strategies for individuals with long-COVID are therefore needed.

Regarding the influence of COVID vaccines on the emergence of long-COVID or its symptoms, studies consistently show an association between vaccinations and reduced odds and risk of developing long-COVID [40, 41]. Consequently, ongoing research proposes that COVID-19 vaccines could offer both protective and therapeutic benefits against long-COVID [42]. Although numerous studies provided evidence that the risk of developing long-COVID is lower among vaccinated individuals than in those without a vaccination [14, 15, 43], there seems to be no difference regarding the number of long-COVID symptoms between both groups according to the results found in this study. However, with respect to gender differences, we did observe a higher number of long-COVID symptoms in women compare to men, which aligns with the findings of a previous study by Jensen et al. [44].

Despite the range of symptoms and adverse impact on various domains, most individuals did not seek help in long-COVID outpatient clinics (82.3%) or rehabilitation facilities (78.1%), which might result in a significant economic burden on the worldwide healthcare system and the well-being of those affected.


The current study used a convenience non-probability sampling approach, whereby subjects were chosen not randomly from the population but rather based on their geographical proximity and availability at a given time. In addition, the majority were female and reported a high educational status. Nonetheless, studies have demonstrated that long-COVID occurs more frequently in women, which makes it reasonable for a higher representation of women in long-COVID studies [45]. Given that this study was conducted online, it might not have been accessible to all individuals living with long-COVID in the population. Consequently, the generalization of our results to the total population is limited.

Due to economic reasons, the length of the survey was as short as possible in order to recruit a large number of participants with a little drop-out rate of unanswered questions. Therefore, some parameters (e.g., the Post-COVID-19 functional status [46]) were not collected and should be included in future studies as they might add valuable information to this research topic. In addition, the current study may be affected by two possible sources of bias: Firstly, participants may have had difficulty correctly recalling their symptoms, burden, or the length of their acute illness, especially if their initial infection occurred several months before completing the online survey. In addition, individuals with more severe symptoms might have been more likely to participate in a long-COVID online survey, again compromising the generalizability of the results.

Also, despite enquiring the duration of the acute disease, and the timepoint of the first long-COVID symptoms, we cannot guarantee that all participants meet the current definition of long-COVID with persistence of symptoms being present for at least four weeks following the acute infection. Finally, this study did not provide guidelines for categorizing individuals into “asymptomatic”, “mild”, and”severe” disease courses. Therefore, participants could indicate a severe disease course, for instance, regardless of whether they were hospitalized or not.

Implications for future research

Future studies should raise awareness concerning the effects of COVID-19 tailored rehabilitation possibilities. However, as general treatment for patients is scarce or unavailable [7], multidisciplinary teams need to specialize in rehabilitating the various symptoms associated with this condition. As fatigue (ongoing and constant exhaustion in mental and physical aspects that does not improve with resting/sleeping) and exhaustion (short-term lack of energy that improves after taking a rest), for instance, emerged among the most prevalent symptoms reported, future research should focus on validating the use of techniques such as psychoeducation [47], energy management [47], training based on cognitive-behavioral-therapy [48, 49], mindfulness [50] or relaxation exercises [51] in ameliorating fatigue in patients suffering from long-COVID. In addition, cognitive deficits like memory problems, trouble finding the correct words, and planning-oriented thinking [52, 53] are common long-COVID symptoms and require tailored cognitive rehabilitation programs. Future research on long-COVID should also examine the implications and consequences due to insufficient, incomplete, or discontinued treatment in the acute phase, since a variety of consequences might be associated with it.


Long-COVID represents a highly heterogeneous disease, encompassing a variety of symptoms such as fatigue, cognitive dysfunction, or dyspnea. The impact of this prolonged illness is not yet fully understood, as symptoms can affect multiple domains, including an individuals’ professional and personal life. Multidisciplinary teams and treatments are needed to develop individually tailored rehabilitation approaches, enabling individuals to ameliorate their symptoms and better cope with the substantial burden of long-COVID in the future.

Supporting information

S1 Table. Frequency of acute symptoms and subjective burden (n = 302).

a Multiple modes exist, the smallest value is shown.


S2 Table. Frequency of ongoing symptoms and subjective burden (n = 271).

a Multiple modes exist, the smallest value is shown.


S1 File. Research data.

Koini, Marisa. Characteristics and burden of acute COVID-19 and long-COVID. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2024-01-06.



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