Predictors of COVID-19 vaccine uptake: An online longitudinal study of US Veterans and non-Veterans

BackgroundTo effectively promote vaccine uptake, it is important to understand which people are most and least inclined to be vaccinated and why. PurposeTo identify predictors of COVID-19 vaccine uptake and reasons for non-vaccination. DesignA longitudinal English-language survey study. SettingOnline in December-2020, January-2021, and March-2021. Participants. 930 US respondents (63% Veterans). MeasurementsSurveys included questions about respondents behaviors, well-being, healthcare experiences, and attitudes regarding the pandemic. ResultsThe proportion of respondents who received [&ge;]1-dose of a COVID-19 vaccine increased from 18% in January to 67% in March. Older age predicted vaccine uptake in January (OR=2.02[95%CI=1.14-3.78], p<.001) and March (10.92[6.76-18.05], p<.001). In January, additional predictors of vaccine uptake were higher numeracy (1.48[1.20-1.86], p<.001), COVID-19 risk perceptions (1.35[1.03-1.78], p=.029), and believing it is important that adults get the COVID-19 vaccine (1.66[1.05-2.66], p=.033). In March, additional predictors of vaccine uptake were believing it is important that adults get the COVID-19 vaccine (1.63[1.15-2.34], p=.006), previous (January) COVID-19 vaccine intentions (1.37[1.10-1.72], p=.006), and belief in science (0.84[0.72-0.99], p=.041). Concerns about side effects and the vaccine development process were the most common reasons for non-vaccination. Unvaccinated respondents with no interest in getting a COVID-19 vaccine were younger (0.27[0.09-0.77], p=.016), held negative views about COVID-19 vaccines for adults (0.15[0.08-0.26], p<.001), had lower trust in healthcare (0.59[0.36-0.95], p=.032), and preferred to watch and wait in clinically ambiguous medical situations (0.66[0.48-0.89], p=.007). LimitationsReliance on the accuracy and consistency of self-reported data. ConclusionThese findings offer important insights regarding key predictors of vaccine uptake during the early stages of the COVID-19 vaccine rollout in the US, which can help guide health communications and public outreach. Evidence that attitudes and intentions towards COVID-19 vaccines are important predictors of uptake provides validation for studies which have used these measures and reinforces the need to develop effective strategies for addressing concerns about vaccine safety and development which continue to be at the forefront of vaccine hesitancy. RegistrationThe pre-registration document associated with this manuscript is available at: https://aspredicted.org/MKS_HRZ.