Exposure to "Vaccination Selfies" Relate to Readers' Vaccination Intention: The Moderating Role of Partisan Media Use and the Mediating Role of Affective Responses

As vaccines for COVID-19 become accessible to the U.S. public, vaccinated individuals often post "vaccination selfies" on social media to encourage unvaccinated others to be inoculated. This study explores the relationship between exposure to these vaccination posts and post readers' vaccination intention. Drawn upon the functional affect theories, the authors proposed integral affective responses to the vaccination posts to explain readers' vaccination intention. Social media users' partisan media use was proposed to explain readers' different affective responses. Results from a cross-sectional survey (N = 343) showed that only exposure to proximal others' (e.g., friends), not distal others' (e.g., celebrities), vaccination posts was significantly associated with vaccination intention through positive affective responses. Conservative media use enhanced readers' negative affective response to vaccination posts whereas liberal media use was associated with positive affective responses. The findings highlighted the importance of social norms and positive affection appeals in pro-vaccination campaigns.