Abstract
IMPORTANCE: Cervical cancer remains a major public health challenge in China, and human papillomavirus (HPV) vaccine uptake remains far below the global average. Understanding public responses to national policy interventions is critical for promoting equitable vaccine access and uptake. OBJECTIVE: To assess the association between 2 national HPV vaccination policies (August 2022 age expansion approval for HPV vaccination [policy 1] and January 2023 National Action Plan for Accelerating the Elimination of Cervical Cancer [policy 2]) in China and public discourse and engagement on social media. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study using interrupted time-series analysis of publicly available posts by individual users containing HPV-related and vaccine-related keywords from China's largest text-based social media platform collected between December 2021 and December 2024. Latent Dirichlet allocation topic modeling was used to identify 16 topics grouped into 5 thematic domains. MAIN OUTCOMES AND MEASURES: Changes in the daily trends of public discussions across 5 thematic domains and 16 topics before and after policy implementation using interrupted time-series analysis. RESULTS: This study analyzed 353 530 HPV-related posts on the social media platform from December 2021 to December 2024. Vaccine accessibility discussions initially increased following the age expansion policy (regression coefficient, 0.08; 95% CI, 0.05-0.12; P < .001). After the launch of the National Action Plan, discussions on the theme of vaccine accessibility decreased by 0.11 percentage points per day (95% CI, -0.14 to -0.08; P < .001). Conversely, discussions on awareness and knowledge increased by 0.04 percentage points per day (95% CI, 0.03-0.06; P < .001), as well as gender and sociocultural factors, which increased by 0.04 percentage points per day (95% CI, 0.02-0.06; P < .001). CONCLUSIONS AND RELEVANCE: These findings suggest that national HPV vaccination policies in China were associated with shifts in public discourse, including alleviated access concerns and increased health awareness and gender equity discussions. Social media data can provide timely insights into public responses to health interventions and inform strategies to promote equitable HPV vaccine uptake and cervical cancer elimination.