A Study of Discourse on COVID-19 Vaccines from Conspiracy Communities on Reddit Using Topic Modeling and Sentiment Analysis.

Given the limited research on the content attributes of anti-vaccination discourse regarding COVID-19 vaccines, our study investigated how conspiracy communities on Reddit, which may serve as potential anti-vaccination groups, have framed their discussions about the vaccines. Using topic modeling, we identified six topics including conspiracy theories and vaccine hesitancy, scientific (mis)information, vaccine policies and politics, vaccine efficacy, impact on special groups, and adverse effects. Furthermore, drawing on social identity theory and the concept of echo chambers, we explored the online dynamics of these communities by examining how negative sentiments and user engagement varied across topics. Negative sentiments were strongest in discussions about vaccine efficacy and adverse effects, with vaccine efficacy generating the most fear and sadness, while adverse effects elicited the most anger and disgust. Engagement also varied across topics, with vaccine efficacy and conspiracy theories generating the highest number of comments, and vaccine efficacy receiving the most upvotes. Our study provides valuable insights into the discourse surrounding COVID-19 vaccines within conspiracy communities. The variations across topics offer a more nuanced understanding of this discourse and could inform developing tailored strategies to counter misinformation.