Data Sheet 1_Social media use and expectations predict COVID-19 vaccine side effects: a prospective longitudinal study.docx

However, its connection with the post-vaccination experience itself remains unclear. The present longitudinal study examined how expectations and psychosocial factors are associated with the relationship between exposure to reports of COVID-19 vaccine side effects on social media and observers’ post-vaccination side effect experience.</p>Design and setting<p>Prospective longitudinal study using online surveys.</p>Participants and outcome measures<p>Five hundred thirty-eight adults residing in Australia indicated the burden (i.e., number of symptoms and related severity) of COVID-19 vaccine side effects seen reported by other users on social media and their own expectations of experiencing post-vaccination side effects (T1).

Perceptions of social media and psychosocial beliefs were also measured. Experience of vaccine-attributed side effects were self-reported after participants received their first (T2; n = 299) and second (T3; n = 155) vaccine doses.</p>Results<p>There was a significant positive association between social media side effect burden exposure and the side effect burden experienced after receiving the first dose. Pre-vaccination side effect expectations formed an indirect association between these variables, but not for the exposure-second dose association.