One-size fits all? Evaluating group differences in an integrated social cognition model to understand COVID-19...

Vaccine programs significantly reduce disease burden within a population. The COVID-19 vaccine facilitated a return to "normal"; however, vaccine coverage remains below target levels. Identifying predictors of vaccine uptake is vital for individual and community health. The present study used the Reasoned Action Approach and integrated hazard-specific risk perception, to predict COVID-19 vaccine intention and uptake behavior. Informed by the diffusion of innovations theory, differences in associations and model effects were tested by early adopter status of the seasonal influenza vaccine. We recruited participants online within the United States for a longitudinal survey study. The integrated social cognition model provided an acceptable to ideal fit for both groups but performed better among the not early adopter group with better fit statistics, mostly stronger effect sizes, and greater variance accounted for in intention to vaccinate against COVID-19. Instrumental attitudes toward the COVID-19 vaccine predicted intention for both groups, and uptake among the non-early adopters. Capacity predicted intention among early adopters, and behavior among non-early adopters. Among non-early adopters, subjective norms had a direct effect on intention and an indirect effect on vaccine uptake behavior. Intervention research to support COVID-19 vaccine uptake focusing on the utility of vaccines, fostering self-efficacy, and providing normative information is warranted.