Despite the sheer devastation caused by the COVID-19 pandemic in the United States, vaccine hesitancy is a major barrier to a successful implementation of the vaccine. We apply two moderators to examine the associations of efficacy and expectancies with COVID-19 vaccine intention. Specifically, we use national survey data collected online in 2020 (N = 1264) and a moderated moderated mediation PROCESS model to examine 1) the associations between self-efficacy about COVID-19 and vaccine intention mediated by positive outcome expectancies and 2) moderating roles of individual responsibility and partisan media use. The findings show that the path from efficacy to expectancies is moderated by individual responsibility, while the path from expectancies to vaccine intention is moderated by liberal media use. Our findings support the strategic application of SCT to emphasize the role of personal responsibility in campaigns to encourage vaccination for the COVID-19 virus.