Abstract
The two studies reported in the paper examined (1) the extended parallel process model's (EPPM; Witte 1992) ability to predict and explain college students' COVID-19 vaccination behavior, and (2) the EPPM-related reasons for college students' COVID-19 vaccine hesitancy. Study 1 was a longitudinal study that measured the EPPM constructs at Time 1 and COVID-19 vaccine behavior two months later at Time 2. For danger control, results indicate that perceived threat and perceived efficacy positively predicted intentions and that intentions positively predicted behavior. For fear control, results indicate that perceived threat positively predicted fear, that perceived efficacy did not predict fear, and that fear negatively predicted defensive avoidance, reactance, and fatalism. Study 2 was a cross-sectional survey that assessed EPPM-related reasons for vaccine hesitancy. Results indicate that the main reasons for vaccine hesitancy were related to response efficacy (i.e., participants were concerned about the safety and effectiveness of the vaccine). The theoretical and practical implications of these results are discussed.