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Acceptability of a COVID-19 vaccine among adults in the United States: How many people would get vaccinated?

Our take —

In an online survey of 2,006 US adults in May 2020, a majority (69%) expressed willingness to receive a COVID-19 vaccine when available, and vaccination intentions varied substantially across various demographic (i.e., sex, race), cognitive (i.e., perceived susceptibility and severity), and social factors (i.e., income, political orientation). Vaccine intentions, however, may not align with actual uptake behaviors when candidate COVID-19 vaccines are rolled out in the general U.S. population.

Study design


Study population and setting

In May 2020, 2,006 adults across 50 US States and the District of Columbia were recruited to participate in an online survey assessing willingness to receive a hypothetical vaccine against SARS-CoV-2 when one became available. COVID-19 vaccination intention was measured in a single survey question, but the investigators collapsed response categories, comparing participants who reported “probable” or “definite” willingness to receive a vaccine to those who expressed uncertainty (“not sure”) or reluctance (“probably not willing” or “definitely not willing”).

Summary of Main Findings

A majority (69% total; 48% “definitely” and 21% “probably”) of participants expressed willingness to receive a COVID-19 vaccine when one became available; 17% of participants reported uncertainty about accepting a COVID-19 vaccine in the future. When adjusting for other factors, willingness to accept a COVID-19 vaccine was significantly higher among participants who were male (75% vs. 64%, p<0.01), who lived in households with annual incomes above $50,000 (76% vs. 62% p<0.05), who espoused moderate or liberal political beliefs (73% vs. 59%, p<0.05), who reported a prior COVID-19 diagnosis (85% vs. 68%, p<0.05), and who thought a healthcare provider would recommend the vaccine (76% vs. 30%, p<0.01). Individuals who perceived themselves as susceptible to COVID-19 (prevalence ratio [PR]: 1.05, 95% confidence interval [CI]: 1.01–1.09), who feared severity of COVID-19 infection (PR 1.08, 95% CI: 1.04–1.11), or who perceived a COVID-19 vaccine as effective in preventing disease (PR 1.46, 95% CI: 1.40–1.52) were also significantly more likely to express willingness to receive a COVID-19 vaccine. Uninsured individuals (50% vs. 71%, p<0.05) and participants who expressed concerns about harms associated with COVID-19 vaccination (PR 0.95, 95% CI: 0.92–0.98) were significantly less likely to express willingness to receive a COVID-19 vaccine. Relative to non-Latinx white participants, non-Latinx Black participants were significantly less likely to declare intention to receive a COVID-19 vaccine in the future, and Latinx participants were no more or less willing than non-Latinx white participants to endorse willingness to receive a COVID-19 vaccine. Among factors impacting COVID-19 vaccination intentions, vaccine effectiveness, physician recommendations, personal health history, and COVID-19 burdens in the community were cited most frequently and at higher rates among participants expressing willingness to receive a COVID-19 vaccine, relative to those who were unwilling or uncertain. Potential vaccine side effects were the only factor cited more frequently among participants who were unwilling or uncertain about receiving a COVID-19 vaccine, relative to those who expressed willingness to receive a vaccine.

Study Strengths

The study population included a relatively heterogeneous sample of adults across income strata, racial identities, and residence settings. Vaccine intentions were also measured using an ordinal Likert scale, which allowed investigators to assess COVID-19 vaccine acceptance along a continuum. Factors shaping decision-making around vaccination intentions were also collected in the survey, which are seldom measured in survey research on COVID-19 prevention.


In their statistical models, the investigators collapsed vaccine willingness response options into a binary item; this could result in misclassification of participant’s vaccine intentions and produce misleading results, especially if individuals who are uncertain about accepting a COVID-19 vaccine are substantially different from individuals who express hesitancy and willingness, respectively, to receive a COVID-19 vaccine. Because the study population was an online convenience sample, findings may not be generalizable to the broader U.S. adult population, since participants may be substantially different from non-participants. Lastly, the survey measured intentions to accept a hypothetical COVID-19 vaccine, which had not been developed when this study was conducted; self-reported intentions may, therefore, not reflect actual vaccine uptake behaviors once a COVID-19 vaccine is offered to participants.

Value added

This study highlights sociodemographic and social disparities in self-reported COVID-19 vaccine intentions among U.S. adults, which can support targeted communication efforts to increase vaccine demand in subpopulations expressing higher degrees of COVID-19 vaccine uncertainty or hesitancy.

This review was posted on: 26 February 2021