Changes in Intent, Behavior, and Reasons to Receive COVID-19 Vaccination December 2020-August 2023

Staying up-to-date with COVID-19 vaccination reduces the risk of severe COVID-19 outcomes, yet U.S. uptake remains low. We described changes in intention, behavior, and reasons for receiving COVID-19 vaccines among individuals who completed a primary series and assessed predictors of not receiving an updated vaccine (BA.4/5 bivalent).

We analyzed data from the community-based CHASING COVID Cohort, a sociodemographically diverse sample of U.S. adults enrolled March-July 2020. The study included adults who completed a primary SARS-CoV-2 vaccine series and participated in at least one quarterly follow-up assessment during April-October 2023. Primary exposures were sociodemographic characteristics and COVID-19 history. Outcomes included intentions to receive a COVID-19 vaccine, vaccine uptake, and self-reported reasons for receiving or not receiving COVID-19 vaccine over time between December 2020-August 2023.

Among 4,411 eligible participants, 58% intended to get vaccinated in December 2020 (before broad availability), and 86% received the 2021-2022 vaccine (monovalent) between September 2021-August 2022. However, willingness to receive a bivalent vaccine between October-December 2022 declined by ≥10%. Among those who received the primary series and 2021-2022 vaccine, 56% received the 2022-2023 vaccine. The prevailing reason for non-receipt from Fall 2022-Summer 2023 was doubts about vaccine effectiveness. Logistic difficulties were predominantly reported in Winter 2022 and confusion about eligibility increased in Spring/Summer 2023. Lower bivalent vaccine uptake was observed among younger, female, non-White, less-educated, lower-income, uninsured individuals, and residents of the South or rural/suburban areas. Those with recent SARS-CoV-2 infection or previous long COVID were less likely to receive updated vaccines. Present comorbidities did not impact vaccines uptake.

Findings highlighted a 3-year decline in willingness and receipt of COVID-19 vaccinations following their public introduction. Broad messaging and targeted outreach are needed to reinforce the protection up-to-date COVID-19 vaccination provides against severe illness and death.