Safety, Efficacy, and Ill Intent: Examining COVID-19 Vaccine Perceptions among the New Undervaccinated Moveable Middle in a U.S. Cohort, October 2022.

Individuals who received their primary vaccine series only (with no subsequent booster) may be a new type of "moveable middle" given their receipt of the original COVID-19 vaccination. One population within the moveable middle for whom tailored interventions may be needed is individuals with common mental disorders (CMD). The purpose of this paper is to understand the vaccine perceptions among this new moveable middle-the undervaccinated-and within the undervaccinated to examine the extent to which COVID-19 vaccine perceptions and motivations differ among those with and without symptoms of CMD. Using data from the CHASING COVID Cohort, we examine the relationship between vaccination status, CMD, and vaccine perceptions in the undervaccinated. Among 510 undervaccinated participants who had completed the primary vaccine series but were not boosted, the most common reasons for undervaccination focused on efficacy (not seeing a need for an additional dose, 42.4%; there not being enough evidence that a booster dose is effective, 26.5%; already having had COVID-19, 19.6%). Other concerns were related to safety (long-term side effects, 21.0%; short-term side effects, 17.6%) and logistics (plan to get a booster but haven't had time yet, 18.8%). Overall, the greatest vaccine concerns (over 30%) for the undervaccinated focused on efficacy and safety issues. Symptoms of depression or anxiety were associated with lower levels of vaccine efficacy and greater safety concerns in adjusted models. The implications of our study are that campaigns that are hoping to maximize vaccination uptake should consider focusing on and emphasizing messaging on efficacy and safety issues.