Extensive research has identified prevalent themes and persuasive tactics in anti-vaccination discussions, yet there is a need for systematic examination of how these themes differ and whether their levels of abstractness and concreteness vary in meaningful ways. Guided by construal level theory, this study analyzed Reddit discussions on COVID-19 vaccines to investigate construal level and evidence use across three anti-vaccination themes: conspiracy theories, adverse effects, and vaccine efficacy. Results revealed that conspiracy posts exhibited higher-level construal with greater use of narratives and lesser use of statistics, while efficacy and adverse-effects posts showed lower-level construal, relied more on statistics, and included fewer narratives. For engagement outcomes, a construal fit was observed for statistical evidence, with high-level construal content eliciting more comments and upvotes. By contrast, narrative evidence and content construal level produced a counter-fit pattern for upvoting, likely due to the uniqueness of conspiracy narratives in conveying abstract claims through storytelling. These findings extend construal level theory and provide theoretical guidance for tailoring messages to counter vaccine misinformation.
