Proximal and Distal Psychological Predictors of COVID-19 Vaccine Hesitancy in the U.S.: A Theory-Guided Systematic Review

COVID-19 vaccine hesitancy has been a persistent threat to public health in the US and worldwide. Developing effective interventions to reduce COVID-19 vaccine hesitancy requires a thorough understanding of its psychological roots. Drawing on the Health Belief Model, we developed a proximal–distal framework to conceptually distinguish between proximal (i.e., COVID-19 related) and distal (i.e., COVID-unrelated) psychological determinants of vaccine hesitancy. Guided by this framework, we conducted a systematic review of published quantitative studies examining associations between psychological factors and COVID-19 vaccine hesitancy (k = 90). The review uncovered a total of 20 distinct proximal psychological predictors, among which perceived susceptibility to the COVID-19 virus, perceived severity of COVID-19 infections, and perceived risks and benefits of the COVID-19 vaccine were prominent drivers. In terms of distal psychological predictors, we identified 22 distinct factors, among which Republican affiliation, Democratic affiliation, conservative political ideology, and general attitudes toward vaccines were particularly salient predictors. Collectively, the proposed proximal–distal framework and the identified predictors offer important theoretical and practical implications for understanding and reducing COVID-19 vaccine hesitancy.