When health meets politics: Selective gatekeeping of health experts in Chinese media during COVID-19.

Recent global health crises have underscored the need for adaptive policymaking amid evolving evidence, alongside the political vulnerability of science communication. This study investigates the politics of health policy communication in a system where the government, media, and experts closely coordinate their messaging. We propose a Selective Gatekeeping framework to explain how state and media actors collaborate to amplify scientific voices aligned with policy objectives while marginalizing alternative perspectives. Using China's COVID-19 policy (2020-2022) as a case study, we analyze over 68,000 Weibo posts from the official accounts of People's Daily and Xinhua News Agency. The findings reveal that expert citations were strategically and adaptively employed in response to shifting policy imperatives. Chinese state media preferentially featured health experts holding Party positions who endorsed the zero-COVID approach, and increasingly emphasized such citations as China's stance diverged from global practices. This media-science-policy nexus played a critical role in maintaining public adherence to stringent and evolving pandemic measures. Our findings reveal how media, scientific, and political institutions can converge to produce a discursive environment that privileges coherence over deliberation. The study contributes to understanding health communication as an instrument of legitimacy-building and swift policy action-one that may constrain scientific contestation and public engagement. It highlights the inherent trade-offs between political objectives and scientific autonomy at the heart of contemporary health politics.