As the United States rolled out COVID-19 vaccinations, state health departments attempted to communicate quickly evolving information about vaccines amid political conflict and misinformation. In October 2021, one state health department shut off comments for their social media to deplatform misinformation. To analyze this health department's Facebook page as a discursive space, our study examines user activity on the page through quantitative analysis of engagement metrics and topical clusters and qualitative analysis of user comments from January to October 2021. Our findings show that the common idea of vaccine proponents valuing data while vaccine skeptics prefer anecdote is not represented; antivaccine comments are pervaded with suspicion toward institutions, while provaccine comments largely use unproductive tactics; the two sides largely showed different sets of concerns; engagement was high during critical moments in the pandemic, and a few top influencers tended to dominate comment threads.