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.

鉴于关于针对新冠疫苗的反疫苗言论的内容属性的研究有限，我们的研究调查了Reddit上的阴谋论社区（可能作为潜在的反疫苗群体）如何构建他们对疫苗的讨论。利用主题建模，我们识别出了包括阴谋理论和疫苗犹豫、科学信息（错误信息）、疫苗政策与政治、疫苗效力、对特殊人群的影响以及副作用等六个主题。此外，基于社会认同理论和回音室概念，通过考察不同主题中负面情绪和用户参与度的变化，我们探讨了这些社区的在线动态。

研究发现，在关于疫苗效力和副作用的讨论中，负面情绪最强，其中疫苗效力引发了最多的恐惧和悲伤，而副作用则引起了最多的愤怒和厌恶。在不同的主题之间，用户的参与程度也有所不同，有关疫苗效力和阴谋理论的主题产生了最多评论，并且关于疫苗效力的主题获得了最多的点赞。

我们的研究为新冠疫苗在网络阴谋论社区中的讨论提供了宝贵的见解。不同主题之间的差异性为我们更深入地理解这种言论提供了一个更为细致的理解视角，并可能有助于制定有针对性的策略来应对错误信息。