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Individuals with comorbid conditions have been disproportionately affected by COVID-19. Since regulatory trials of COVID-19 vaccines excluded those with immunocompromising conditions, few patients with cancer and autoimmune diseases were enrolled. With limited vaccine safety data available, vulnerable populations may have conflicted vaccine attitudes.
We assessed the prevalence and independent predictors of COVID-19 vaccine hesitancy and acceptance among individuals with serious comorbidities and assessed self-reported side effects among those who had been vaccinated.
We conducted a cross-sectional, 55-item, online survey, fielded January 15, 2021 through February 22, 2021, among a random sample of members of Inspire, an online health community of over 2.2 million individuals with comorbid conditions. Multivariable regression analysis was utilized to determine factors independently associated with vaccine hesitancy and acceptance.
Of the 996,500 members of the Inspire health community invited to participate, responses were received from 21,943 individuals (2.2%). Respondents resided in 123 countries (United States: 16,277/21,943, 74.2%), had a median age range of 56-65 years, were highly educated (college or postgraduate degree: 10,198/17,298, 58.9%), and had diverse political leanings. All respondents self-reported at least one comorbidity: cancer, 27.3% (5459/19,980); autoimmune diseases, 23.2% (4946/21,294); chronic lung diseases: 35.4% (7544/21,294). COVID-19 vaccine hesitancy was identified in 18.6% (3960/21,294), with 10.3% (2190/21,294) declaring that they would not, 3.5% (742/21,294) stating that they probably would not, and 4.8% (1028/21,294) not sure whether they would agree to be vaccinated. Hesitancy was expressed by the following patients: cancer, 13.4% (731/5459); autoimmune diseases, 19.4% (962/4947); chronic lung diseases: 17.8% (1344/7544). Positive predictors of vaccine acceptance included routine influenza vaccination (odds ratio [OR] 1.53), trust in responsible vaccine development (OR 14.04), residing in the United States (OR 1.31), and never smoked (OR 1.06). Hesitancy increased with a history of prior COVID-19 (OR 0.86), conservative political leaning (OR 0.93), younger age (OR 0.83), and lower education level (OR 0.90). One-quarter (5501/21,294, 25.8%) had received at least one COVID-19 vaccine injection, and 6.5% (1390/21,294) completed a 2-dose series. Following the first injection, 69.0% (3796/5501) self-reported local reactions, and 40.0% (2200/5501) self-reported systemic reactions, which increased following the second injection to 77.0% (1070/1390) and 67.0% (931/1390), respectively.
In this survey of individuals with serious comorbid conditions, significant vaccine hesitancy remained. Assumptions that the most vulnerable would automatically accept COVID-19 vaccination are erroneous and thus call for health care team members to initiate discussions focusing on the impact of the vaccine on an individual’s underlying condition. Early self-reported side effect experiences among those who had already been vaccinated, as expressed by our population, should be reassuring and might be utilized to alleviate vaccine fears. Health care–related social media forums that rapidly disseminate accurate information about the COVID-19 vaccine may play an important role.
The rapid development of safe and effective vaccines against SARS-CoV-2 may stem the global COVID-19 pandemic. However, vaccine hesitancy—the reluctance or refusal to vaccinate—has emerged as a major worldwide public health concern, especially as it may impair the ability to reach herd immunity status [
Individuals with comorbid conditions have been disproportionately affected by COVID-19. A US review of nearly 500,000 commercially insured COVID-19 patients noted that, although only 51.7% had pre-existing conditions, 83.3% of the COVID-19–related deaths occurred among those with comorbidities. The risk of dying from COVID-19 was strongly correlated with the number of comorbidities, nearly doubling with a single comorbid condition and increasing 8-fold with 5 or more conditions [
COVID-19 vaccine allocation policies have prioritized individuals with serious comorbidities [
Survey participants were recruited from Inspire (Arlington, VA), an online health community of over 2.2 million individuals with comorbid conditions and their caregivers. Members anonymously engage with others with similar conditions through discussion posts and direct messaging. The community, with members residing in over 100 countries, represents over 3600 comorbid conditions including cancer, autoimmune diseases, rare diseases, and other chronic conditions.
When individuals join Inspire, they are given the opportunity of opting in to receive invitations for research projects. For this study, email invitations were sent on a daily basis to a computer-generated random sample of members who had agreed to receive research survey requests. Prior to participating in this study, individuals completed a consent form (approved by WCG IRB, Puyallup, WA) that detailed the purpose of the research. Participants were able to withdraw at any time throughout the survey. Participants were not compensated. Duplicate responses were removed by review of unique tokens assigned to participants.
The survey consisted of 55 items, with initial responses leading to a potential addition of 8 follow-up questions. The survey was implemented using Alchemer, a web-based survey tool. Survey logic, programming, testing, and data validation were done via Alchemer. Items used to assess vaccine perception and hesitancy were adapted from Pew Research Center’s American Trends Panel 2020 survey, with additional questions added and linguistic adjustments [
Independent measures in the survey detailed demographics including age, education level, political leaning, ethnicity, income, residence (country of residence; if in the United States, state of residence), patient history of disease including specific disease, current treatment status if a cancer patient, and gender. Dependent measures included plans to receive the vaccine and attitudes and concerns toward the COVID-19 vaccines.
Interest in obtaining the vaccine was evaluated through the question, “Do you plan to get the COVID-19 vaccine when one is available?” This item was evaluated with options of “I already got it,” “I’ve tried but have not been able to get it,” “Definitely,” “Probably,” “Unsure,” “Probably not,” and “Definitely not.” For the purpose of analysis, participants who responded with “Definitely not,” “Probably not,” or “Unsure” were considered to be “vaccine hesitant.” Participants indicating the other responses, including those who had already received the COVID-19 vaccine, were considered to be “vaccine acceptant.”
Attitudes and concerns about the vaccine were elicited through the question, “What are your concerns about the vaccine? Check all that apply.” The possible responses included the following: “I do not believe I need it,” “I do not think it was developed responsibly,” “I do not trust the government has insured that the vaccines are safe and effective,” “I do not trust vaccines in general,” “I do not trust the COVID-19 vaccine in particular,” “I am concerned that the COVID-19 vaccine is too new,” “I want to see how others respond first,” “Concerns over the role of politics in the development process,” “It is too difficult to get vaccinated,” “I am concerned with contracting the coronavirus from the vaccine,” “I am concerned about the side effects or discomfort,” and “I have religious objections.”
As concerns about side effects may contribute to COVID-19 vaccine hesitancy and since immunocompromised individuals were largely excluded from COVID-19 vaccine trials, we sought to obtain additional information about the experiences of individuals who had received the vaccine. Specifically, we included questions about the type of vaccine received and which (if any) side effects were experienced. The list of reportable symptoms and effects from the vaccine included on the survey were adapted from the Pfizer/BioNTech BNT162b2 mRNA COVID-19 Vaccine FDA Briefing Report [
Two-way cross tabulations were used to summarize sociodemographic variables, behavioral and public health belief variables, and comorbid disease variables across vaccine hesitancy. Pearson chi-squared tests were performed to assess for statistical significance in the differences between groups. Univariate logistic regression analyses were performed to assess independent relationships between several variables and the dichotomous vaccine acceptance variable.
Multivariate logistic regression analysis was performed to assess the relationship between multiple predictor variables and the dichotomized vaccine acceptance variable. Two-sided, design-based tests and an alpha level of .05 was used to evaluate statistical significance in all chi-squared, F test, and logistic regression analyses. No backward selection was used, and all variables remained in the model regardless of their significance level. All data management and analysis were conducted using SPSS Version 28 (IBM Corp, Armonk, NY).
This study was funded by Inspire, which was responsible for the study design; the collection, analysis, and interpretation of the data; and the decision to approve publication of the finished manuscript.
Invitations to participate in this survey were sent to 996,500 members of the Inspire health community between January 15, 2021 and February 22, 2021. Responses to the survey request were received from 21,943 individuals (2.2%), of which 17,115 completed the entire survey (1.7% of those invited and 78.0% of respondents). The median age range of respondents was 56-65 years, which appeared older than the Inspire community median age range of 40-49 years. The survey respondents were mostly female (15,696/20,685, 75.9%), similar to the general Inspire community (77%). There was minimal self-identification as belonging to a racial or ethnic minority within the respondent population.
Inspire’s membership is made up of both individuals with declared illnesses and their caregivers. However, caregivers who wished to participate in this study separate from their loved ones were instructed to complete a separate survey based on their own attitudes and to document their own health status. All participants (21,943/21,943, 100%) in this project indicated at least one comorbid condition. A cancer diagnosis was self-reported by 27.3% (5459/19,980) of responding participants, 23.2% (4946/21,294) had an autoimmune disease, and 35.4% (7544/21,294) were diagnosed with a chronic lung disease.
Respondents were highly educated, with 58.9% (10,198/17,298) holding college or postgraduate degrees. Political leanings were diverse, with 31.6% (5683/17,967) self-declaring liberal tendencies, 20.7% (3711/17,967) self-declaring as conservative, 24.3% (4357/17,967) self-declaring as independent, and 23.5% (4216/17,967) preferring not to declare. Respondents lived in 123 countries, with 74.2% (16,277/21,943) residing in the United States, 8.5% (1855/21,943) in Canada, 8.1% (1781/21,943) in the United Kingdom, 3.1% (688/21,943) in Australia, and the remaining 6.1% (1342/21,943) in Europe, Central, South America and the Caribbean, the Middle East, the Russian Federation, Africa, or the Far East.
Among the 21,294 individuals with cancer, autoimmune diseases, or other serious diseases who responded to survey questions about their attitudes on vaccination, 18.6% (3960/21,294) indicated COVID-19 vaccine hesitancy, including 10.3% (2190/21,294) who declared that they would not receive the vaccine, 3.5% (742/21,294) who stated that they would probably not, and 4.8% (1028/21,294) who were not sure whether they would agree to be vaccinated. By contrast, 25.8% (5501/21,294) respondents reported that they had already received at least one COVID-19 vaccine injection by February 22, 2021. Of the US participants, 29.6% (4813/16,277) had already undergone vaccination. Among participants from other countries, 688 had undergone vaccination including 68% of participants living in Israel, 27% in the United Kingdom, 4% in Canada, and none in Australia. Additionally, 6.9% (1462/21,294) had tried but had been unable to obtain the vaccine, 43.9% (9342/21,294) definitely planned to undergo vaccination, and 4.8% (1029/21,294) indicated that they probably would undergo vaccination, leading to an overall vaccine acceptance of 81.4% (17,334/21,294).
As shown in
Opinions about public health policy also shaped vaccine hesitancy attitudes. In our study population of individuals with severe illnesses, 96.2% (18,376/19,468) reported routinely wearing masks. Although a greater proportion of mask wearers reported vaccine acceptance than those who reported not wearing masks, 18.4% (3444/18,736) of mask wearers remained vaccine hesitant. Most (16,269/21,294, 78.2%) respondents routinely received an influenza vaccination—a cohort with a vaccination acceptance prevalence of 91.6% (14,905/16,269) compared with the 45.9% (2083/4545) acceptance prevalence among those who did not routinely receive an influenza vaccine (
Vaccine hesitancy by age, gender, ethnicity, education level, and political leanings among individuals with serious comorbidities (n=21,294) using Inspire between January 15, 2021 and February 22, 2021.
Characteristic | Overall sample (n=21,294), n (%) | COVID-19 vaccine received or definitely or probably will receive the vaccine (n=17,334), n (%) | Definitely or probably will not receive the vaccine or unsure about receiving the vaccine (n=3960), n (%) | |
|
||||
|
<26 | 381 (1.9) | 289 (75.9) | 92 (24.1) |
|
26-35 | 1315 (6.5) | 928 (70.6) | 387 (29.4) |
|
36-45 | 2513 (12.4) | 1871 (74.5) | 642 (25.5) |
|
46-55 | 3309 (16.4) | 2541 (76.8) | 768 (23.2) |
|
56-65 | 5288 (26.2) | 4340 (81.1) | 948 (17.9) |
|
66-75 | 5591 (27.6) | 4961 (88.7) | 630 (11.3) |
|
>75 | 1828 (9.0) | 1649 (90.2) | 179 (9.8) |
|
||||
|
Male | 4989 (24.1) | 4237 (84.6) | 752 (15.4) |
|
Female | 15,696 (75.9) | 12,802 (81.5) | 2894 (18.5) |
|
||||
|
White | 17,354 (89.2) | 14,487 (83.5) | 2867 (16.5) |
|
Black or African American | 514 (2.6) | 391 (76.1) | 123 (23.9) |
|
Hispanic or Latino | 614 (3.2) | 509 (82.9) | 105 (17.1) |
|
Asian | 627 (3.2) | 520 (82.9) | 107 (17.1) |
|
Hawaiian/Pacific Islander | 22 (0.1) | 15 (67.2) | 7 (31.8) |
|
Native American/Alaskan | 132 (0.7) | 88 (66.7) | 44 (33.3) |
|
Other | 479 (2.5) | 337 (70.4) | 142 (29.6) |
|
Prefer not to answer | 706 (3.6) | 306 (43.4) | 400 (56.6) |
|
||||
|
High school or less | 1640 (9.5) | 1246 (75.9) | 394 (24.1) |
|
Vocational or associate degree | 2546 (14.7) | 1955 (76.8) | 591 (23.2) |
|
Some college | 2914 (16.8) | 2302 (79.0) | 612 (21.0) |
|
College degree | 4448 (25.7) | 3748 (84.3) | 700 (15.7) |
|
Postgraduate | 5750 (33.2) | 5054 (87.9) | 696 (12.1) |
|
||||
|
Liberal | 5683 (31.6) | 5401 (95.0) | 282 (5.0) |
|
Conservative | 3711 (20.7) | 2653 (71.5) | 1058 (28.5) |
|
Independent | 4357 (24.3) | 3520 (80.8) | 837 (19.2) |
|
Prefer not to answer | 4216 (23.5) | 3185 (75.5) | 1031 (24.5) |
an=20,225.
bn=20,685.
cn=19,465.
dn=17,298.
en=17,967.
Responses to the question, “Do you plan to get the COVID-19 vaccine when one is available?”, as an indicator of vaccine hesitancy, by mask wearing, routine influenza vaccination, belief in media coverage accuracy, and trust in responsible development among individuals with serious comorbidities (n=21,294) using Inspire between January 15, 2021 and February 22, 2021.
Characteristic | Overall sample (n=21,294), n (%) | Responses | ||
|
|
“I already got it,” “I’ve tried but have not been able to get it,” “Definitely,” “Probably”, n (%) | “Unsure,” “Probably not,” “Definitely not”, n (%) | |
|
||||
|
Always/sometimes wears a mask | 18,736 (96.2) | 15,292 (81.6) | 3444 (18.4) |
|
Rarely/never wears a mask | 732 (3.8) | 557 (76.1) | 175 (23.9) |
|
||||
|
Usually gets a flu vaccine | 16,269 (78.2) | 14,905 (91.6) | 1364 (8.4) |
|
No flu vaccine | 4545 (21.8) | 2083 (45.9) | 2462 (54.1) |
|
||||
|
Yes or generally yes | 10,465 (53.8) | 8541 (81.6) | 1924 (18.4) |
|
No or generally no | 3084 (15.8) | 2449 (79.4) | 635 (20.6) |
|
Mixed | 5910 (30.3) | 4852 (82.1) | 1058 (17.9) |
|
||||
|
Yes | 12,498 (61.2) | 12,292 (98.4) | 206 (1.6) |
|
Probably so | 3900 (19.1) | 3494 (89.6) | 406 (10.4) |
|
Not sure | 1837 (9.0) | 750 (40.8) | 1087 (59.2) |
|
Probably not | 632 (3.1) | 57 (9.0) | 575 (91.0) |
|
No | 1537 (7.5) | 25 (1.6) | 1512 (98.4) |
an=19,468.
bn=20,814.
cn=19,459.
dn=20,409.
Of the survey respondents, 9.0% (1906/21,294) self-reported a prior history of COVID-19 infection, and an additional 5.1% (1085/21,294) believed that they had experienced symptoms suggestive of COVID-19 without confirmation (or were unsure). Although current guidelines recommend vaccination despite prior infection, 34.7% (1039/2991) of these individuals were vaccine hesitant. By contrast, among the more than 17,000 respondents who claimed no prior exposure to SARS-CoV-2, only 15.8% (2758/17,460) were vaccine hesitant (
Responses to the question, “Do you plan to get the COVID-19 vaccine when one is available?”, as an indicator of vaccine hesitancy, among individuals with serious comorbidities (n=21,294) who used Inspire between January 15, 2021 and February 22, 2021, according to prior COVID-19 infection history (n=20,451).
Previous COVID-19 infection status | Overall sample (n=20,451), n (%) | Responses | |
|
|
“I already got it,” “I’ve tried but have not been able to get it,” “Definitely,” “Probably”, n (%) | “Unsure,” “Probably not,” “Definitely not”, n (%) |
Had COVID-19 | 1906 (9.0) | 1209 (63.4) | 697 (36.6) |
Unsure if had COVID-19 | 1085 (5.1) | 743 (68.5) | 342 (31.5) |
Did not have COVID-19 | 17,460 (85.4) | 14,702 (84.2) | 2758 (15.8) |
Among the 5459 individuals with cancer, 13.4% (731/5459) indicated vaccine hesitancy, including 13.2% (193/1463) of those who were currently receiving treatment and 13.5% (538/3996) of those who had completed prior treatment. Those who were not being treated for cancer had a vaccine hesitancy prevalence of 20.3% (2954/14,521). The difference in vaccine hesitancy proportions between those being treated for cancer and those not being treated for cancer was statistically significant (
Responses to the question, “Do you plan to get the COVID-19 vaccine when one is available?”, as an indicator of vaccine hesitancy, among individuals with serious comorbidities (n=21,294) using Inspire between January 15, 2021 and February 22, 2021.
Characteristic | Overall sample (n=21,294), n (%) | Responses | |||||
|
|
“I already got it,” “I’ve tried but have not been able to get it,” “Definitely,” “Probably”, n (%) | “Unsure,” “Probably not,” “Definitely not”, n (%) | ||||
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|||||||
|
Yes, in treatment | 1463 (7.3) | 1270 (88.8) | 193 (13.2) | |||
|
Yes, past treatment | 3996 (20.0) | 3458 (86.6) | 538 (13.5) | |||
|
No cancer | 14,521 (72.7) | 11,567 (79.7) | 2954 (20.3) | |||
|
|||||||
|
Yes | 4946 (23.2) | 3984 (80.6) | 962 (19.4) | |||
|
No | 16,348 (76.8) | 13,405 (82.0) | 2943 (18.0) | |||
|
|||||||
|
Yes | 7544 (35.4) | 6200 (82.2) | 1344 (17.8) | |||
|
No | 13,750 (64.6) | 11,134 (81.0) | 2616 (19.0) | |||
|
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|
Yes | 5358 (25.2) | 4395 (82.0) | 963 (18.0) | |||
|
No | 15,936 (74.8) | 13,068 (82.0) | 2868 (18.0) | |||
|
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|
Yes | 1400 (6.6) | 1134 (81.0) | 266 (19.0) | |||
|
No | 19,894 (93.4) | 16,353 (82.2) | 3541 (17.8) | |||
|
|||||||
|
Yes | 3041 (14.3) | 2443 (80.3) | 598 (19.7) | |||
|
No | 18,253 (85.7) | 14,968 (82.0) | 3285 (18.0) |
an=19,980.
In the univariate logistic regression analysis, having received a routine influenza vaccine was associated with COVID-19 vaccine acceptance (odds ratio [OR] 1.24). Those who reported routinely receiving an influenza vaccine had 1.24 times the odds of being COVID-19 vaccine acceptant. Those who reported having trust that the COVID-19 vaccine was developed responsibly had 2.07 times the odds of being vaccine acceptant (OR 2.07). Those who reported being previously infected with COVID-19 had 0.93 times the odds of being vaccine hesitant (OR 0.93). Those who reported an independent political leaning or liberal political leaning had 1.12 and 1.14 times the odds, respectively, of being vaccine acceptant when compared with those who reported a conservative political leaning. Respondents residing within the United States had 1.03 times the odds of reporting vaccine acceptance than those living outside the United States. Those with an age higher than the median age of the study had 1.12 times the odds (or a 12% increase in odds) of reporting vaccine acceptance compared with those below the median age, while those at the median age had 0.99 times the odds of being vaccine acceptant compared with those below the median age. Moreover, those with some college education had 1.03 times the odds of being vaccine acceptant compared with those with a high school degree or less, while those with at least a 4-year degree had 1.04 times the odds of being vaccine acceptant compared with those with a high school degree or less. Smoking status was not significantly associated with vaccine acceptance. Men had 0.98 times the odds of being vaccine acceptant than women. Those diagnosed with cancer had 1.03 times the odds of being vaccine acceptant compared with those not diagnosed with cancer, and those who reported mask wearing had 1.02 times the odds of being vaccine acceptant (
Univariate logistic regression of vaccine acceptance among individuals with serious comorbidities (n=21,294) using Inspire between January 15, 2021 and February 22, 2021.
Variable | Odds ratio (95% CI) | ||||
Routine influenza vaccine | 1.24 (1.23-1.25) | <.001 | |||
Trust in responsible development of COVID vaccine | 2.07 (2.05-2.09) | <.001 | |||
Prior COVID infection | 0.93 (0.92-0.94) | <.001 | |||
|
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|
Conservative political leaning (reference) | -a | - | ||
|
Independent | 1.12 (1.10-1.13) | .003 | ||
|
Liberal leaning | 1.14 (1.12-1.15) | <.001 | ||
Residence (United States vs outside the United States) | 1.03 (1.02-1.04) | <.001 | |||
|
|||||
|
Age below the median (reference) | - | - | ||
|
Median age | 0.99 (0.98-0.99) | <.001 | ||
|
Age above the median | 1.12 (1.11-1.13) | <.001 | ||
|
|||||
|
High school and less (reference) | - | - | ||
|
Some college, associate degree | 1.03 (1.03-1.04) | <.001 | ||
|
At least a college degree | 1.04 (1.02-1.06) | <.001 | ||
Smoking status | 1.01 (1.00-1.02) | .17 | |||
Gender | 0.98 (0.97-0.99) | .001 | |||
Cancer diagnosis | 1.03 (1.02-1.04) | .001 | |||
Mask wearing | 1.02 (1.01-1.03) | <.001 |
aReference category.
To understand the impact of these independent variables on vaccine acceptance, a multivariate logistic regression analysis was performed to predict those who had received or planned to receive their vaccination by February 20, 2021. Overall, our model was a statistically significant predictor of vaccine acceptance, with an adjusted
Multivariate logistic regression analysis of vaccine acceptance among individuals with serious comorbidities (n=21,294) using Inspire between January 15, 2021 and February 22, 2021.
Variable | Odds ratio (95% CI) | ||
Routine influenza vaccine | 1.08 (1.07-1.08) | <.001 | |
Trust in responsible development of COVID vaccine | 1.86 (1.84-1.88) | <.001 | |
Prior COVID infection | 0.97 (0.96-0.98) | <.001 | |
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|||
|
Independent | 1.02 (1.01-1.03) | <.001 |
|
Liberal | 1.06 (1.05-1.07) | <.001 |
Residence (United States vs outside the United States) | 0.98 (0.98-0.99) | <.001 | |
|
|||
|
Median age | 1.01 (0.99-1.02) | .07 |
|
Above the median age | 1.02 (1.01-1.03) | <.001 |
|
|||
|
Some college | 1.00 (0.99-1.01) | .56 |
|
College and graduate school | 0.99 (0.98-1.01) | .68 |
Smoking status | 1.01 (1.00-1.02) | .004 | |
Gender | 1.00 (0.99-1.02) | .67 | |
Cancer diagnosis | 1.00 (0.99-1.00) | .45 | |
Mask wearing | 0.10 (0.99-1.01) | .96 |
Factors associated with vaccine acceptance after controlling for other covariates included routine influenza vaccination, political leaning, age (below the median versus median range versus above the median), country of residence (in the United States versus living outside the United States), prior COVID-19 infection, and trust in responsible development of the COVID-19 vaccine. Routine receipt of influenza vaccination remained a positive predictor of COVID-19 vaccine acceptance after controlling for other covariates, with an OR of 1.08, meaning participants who reported regularly receiving the flu shot had 1.08 times the odds of being vaccine acceptant. Trust in responsible development of the vaccine was also a significant predictor of COVID-19 vaccine acceptance, with an OR of 1.86, meaning that those who reported having trust in the development of the vaccine had 1.86 times the odds of receiving it than those that reported not having trust in the development. Those residing in the United States (OR 0.98) had 0.98 times the odds of accepting the vaccine than those living outside the United States. Those who reported never smoking also had slightly greater odds of vaccine acceptance (OR 1.01). By contrast, vaccine acceptance was less likely with a history of prior COVID-19 infection (OR 0.97). After controlling for other variables, those reporting an independent political leaning had 1.02 times the odds of being vaccine acceptant compared with those who reported a conservative political leaning, and those who reported a liberal political leaning had 1.02 times the odds of being vaccine acceptant than those who reported a conservative political leaning. Age remained a statistically significant predictor of vaccine acceptance after controlling for other variables. Those with an age higher than the median age of the study had 1.02 times the odds of reporting vaccine acceptance compared with those below the median age, while those at the median age had 1.01 times the odds of being vaccine acceptant compared with those below the median age. When controlling for other variables, gender was no longer a statistically significant predictor of vaccine acceptance. The same is true for education level, cancer diagnosis, and mask wearing.
Of the 3960 respondents who indicated COVID-19 vaccine hesitancy, apprehension regarding the newness of the vaccine was the most commonly cited reason for hesitancy, expressed by 53.1% (2104/3960) of hesitant respondents. Concerns about the safety of the vaccine and a general distrust of the development process (including governmental oversight) also were common (
Concerns about the COVID-19 vaccine among the vaccine-hesitant individuals (n=3960) using Inspire between January 15, 2021 and February 22, 2021.
Responses to the question: “What are your concerns about the vaccine? Check all that apply.” | Overall (n=3960), n (%) | United States (n=2817), n (%) | Outside the United States (n=1143), n (%) |
I am concerned the COVD-19 vaccine is too new. | 2104 (53.1) | 1532 (54.4) | 572 (50.0) |
I do not trust the government has ensured that the vaccines are safe and effective. | 1900 (48.0) | 1365 (48.5) | 535 (46.8) |
I am concerned about side effects and discomfort. | 1738 (43.9) | 1219 (43.4) | 519 (45.5) |
I do not trust the COVID-19 vaccine in particular. | 1571 (39.7) | 1126 (40.0) | 445 (38.9) |
I have concerns over the role of politics in the development process. | 1533 (38.7) | 1112 (39.4) | 421 (36.8) |
I want to see how others respond first. | 1319 (33.3) | 974 (34.6) | 345 (30.2) |
I do not think it was developed responsibly. | 1313 (33.2) | 922 (32.7) | 391 (34.2) |
I do not believe I need it. | 869 (22.0) | 589 (20.9) | 280 (24.5) |
I do not trust vaccines in general. | 832 (21.0) | 591 (21.0) | 292 (25.5) |
I have religious objections. | 331 (8.4) | 262 (9.3) | 69 (6.0) |
I am concerned with contracting the coronavirus from the vaccine. | 327 (8.3) | 221 (7.8) | 106 (9.3) |
It is too difficult to get vaccinated. | 86 (2.2) | 74 (2.6) | 12 (1.0) |
As of the study cutoff, 5501 (5501/21,294, 25.8%) survey respondents had received at least one COVID-19 vaccination (Pfizer-BioNTech: 2640/5501, 48.0%; Moderna: 2586/5501, 47.0%; Oxford-AstraZeneca: 55/5501, 1.0%; other/unknown: 220/5501, 4.0%). A 2-injection series was completed by 6.5% (1390/21,294) of respondents. Following the first injection, 69.0% (3796/5501) self-reported experiencing local adverse events, and 40.0% (2200/5501) self-reported systemic reactions. Pain at the injection site was the most commonly self-reported side effect. Fatigue and myalgias were the most commonly self-reported systemic side effects. Among those who had received 2 vaccine injections (n=1390), the frequencies of self-reported local and systemic reactions increased following the second injection, to 77.0% (1070/1390) and 67.0% (931/1390), respectively (
Self-reported localized reactions to COVID-19 vaccination among individuals with cancer, autoimmune diseases, or other serious comorbidities and/or their caregivers (n=5501 who received an initial vaccine dose; n=1390 who completed a 2-dose series).
Self-reported systemic reactions to COVID-19 vaccination among individuals with cancer, autoimmune diseases, or other serious comorbidities and/or their caregivers (n=5501 who received an initial vaccine dose; n=1390 who completed a 2-dose series).
Among respondents who had received a vaccination with the Pfizer-BioNTech (n=2640) or Moderna (n=2586) vaccines, the initial injection led to overall self-reported localized side effects among 65.0% (1716/2640) and 75.0% (1939/2586), respectively. Local reactions increased to 72.0% (480/667) and 85.0% (368/433) with the second booster Pfizer-BioNTech and Moderna injections, respectively. A more dramatic increase in self-reported systemic side effects was noted with the second injection, with overall systemic effects rising from 37.0% (977/2640) to 62.0% (413/667) and 40.0% (1034/2586) to 77.0% (333/433), with the Pfizer-BioNTech and Moderna vaccines, respectively.
Of the 5459 cancer patients who responded to the survey, 30.0% (1638/5459) had received 1 injection, and 6.0% (325/5459) completed both vaccine injections
In this survey of nearly 22,000 individuals with serious comorbid conditions conducted shortly after vaccine regulatory approvals, 8 in 10 respondents reported a willingness to receive the COVID-19 vaccine. This high level of vaccine acceptance in a community of vulnerable individuals who regularly seeks medical information through participation in an online health forum compares favorably with reports in public opinion polls drawn from general populations taken at the same timeframe [
However, almost 1 in 5 respondents to our survey, all of whom had comorbidities, reported COVID-19 vaccine hesitancy. This was a similar hesitancy prevalence as reported in general population polls at the time [
We identified multiple factors that were independently associated with vaccine hesitancy. Lack of trust in COVID-19 vaccine development, including the rapidity and politicization of the process, was expressed by our comorbid cohort but is a view not unique to our population [
Few studies have specifically explored issues of COVID-19 vaccine hesitancy among patients with severe comorbid conditions or strategies to increase acceptance in high-risk populations. As these individuals already have ongoing health care contact, the potential influence of their physicians should not be ignored. A Korean study noted that, although only 61.8% of their cancer patients were initially willing to receive the COVID-19 vaccine, acceptance increased by 30% if their oncologist recommended it [
Establishing trust in science and vaccine development is critical to reducing vaccine hesitancy. Despite our population having ongoing contact with the health care system (by virtue of their underlying diseases) and routinely engaging in an online health-related forum, we noted that issues regarding trust were expressed by over 40% of vaccine-hesitant respondents. A survey of nearly 6000 US health care workers, older adults, frontline essential workers, other essential workers, and individuals with a high-risk chronic condition conducted in early 2021 identified that lack of trust in the vaccine approval and development processes was the most important trust issue. Other domains of trust (in vaccine safety and efficacy, in health care providers, in sources of information, and generalized trust) were of lesser importance [
The potential role of social media in combating the COVID-19 pandemic cannot be underestimated. This study was sponsored by an online health community whose international membership shares medical information and personal experiences via hundreds of disease-specific forums. Our motivation for designing the study was to increase our membership’s knowledge and encourage discussions regarding COVID-19 vaccine experiences. The rapid enrollment of nearly 22,000 respondents with serious diseases over a 5-week period, with thousands more viewing the online results, attests to the potential influence of the worldwide web on health issues. An infodemiology study of over 650,000 “tweets” from November 2020, prior to the release of vaccines, identified that the main themes driving vaccine hesitancy were concerns of safety, efficacy, freedom, and mistrust in institutions (either the government or multinational corporations) [
As noted in our survey, COVID-19 vaccine acceptance and hesitancy are a global issue. Respondents residing outside the United States were more likely to exhibit vaccine hesitancy, but the reasons for concerns about vaccination appeared similar. A systematic review of World Health Organization regions noted great variability in acceptance of the vaccine, with lowest rates in Hong Kong and the Democratic Republic of the Congo, 2 countries with recent political instability. In contrast, China, Indonesia, and Malaysia all reported hesitancy prevalence below 10%, potentially a reflection of their early experiences with SARS-CoV-2. Across Europe, hesitancy varied greatly from 20% in the United Kingdom to almost 60% in Italy [
Limited data exist regarding the safety and effectiveness of COVID-19 vaccination among immunocompromised individuals (with the exception of individuals infected with HIV) since they were excluded from the regulatory phase 3 trials. Therefore, we expected safety concerns to dominate vaccine hesitancy concerns in our survey [
We recognize several limitations to our study. The survey was conducted in January 2021 and February 2021, shortly after the release of the COVID-19 vaccine, and represents attitudes from a single time point. As additional information about the safety and efficacy of vaccination becomes available to our participants, we expect that attitudes might change. Indeed, serial tracking polls conducted by the Kaiser Family Foundation have noted an increase in the acceptance of vaccination over time, although most of the changes in attitudes have occurred among the “wait and see” populations, with little movement among the vaccine-hesitant cohort [
In summary, our online survey highlights a high level of acceptance of COVID-19 vaccines among vulnerable individuals. However, the finding that 1 in 5 remains vaccine hesitant is of concern and points to a need for additional efforts. Although governmental mandates or financial incentives are being considered, educational efforts must continue [
odds ratio
None declared.