Examining the roles of social media information exposure and seeking on COVID-19 vaccination through the S-O-R model: A two-wave panel in Hong Kong

This study draws upon the stimulus-organism-response (S–O-R) framework in examining the influence of stimulus factors (i.e., passive exposure to and active information seeking for COVID-19 vaccine information on social media) on users' internal psychological mechanisms (i.e., perceived information overload and psychological reactance) and vaccination behavior. We collected two-wave online panel data (W₁ N = 411, W₂ N = 264) in Hong Kong and tested our hypothesized model using structural equation modeling. The results showed that passive information exposure and active information seeking on social media were positively associated with both vaccination initiation (i.e., receiving the first dose) and full vaccination (i.e., completing the recommended 3-dose schedule at W2). We identified different mediation pathways from passive information exposure and active information seeking to vaccine skepticism through perceived information overload and psychological reactance. Specifically, a double-edged sword effect was found for active information seeking. Active information seeking was associated with lower vaccine skepticism both directly and indirectly through lower psychological reactance. On the other hand, active information seeking was associated with higher perceived information overload, which in turn was associated with higher psychological reactance and subsequently higher vaccine skepticism. Passive information exposure indirectly affected psychological state and vaccine skepticism through higher active information seeking. These findings contribute to the literature on the impact of social media use on vaccination behavior in the context of public health emergencies and offer practical implications for governments and social media platforms in risk communication and vaccination promotion.