U.S. Public Health Policy Shifts Under the Second Trump Administration and Implications for the Republic of Korea's Health Security.

OBJECTIVES: This report evaluates the U.S. public health policy shifts enacted by the 2025 Trump administration and assesses their implications for global health cooperation, evidence-based policymaking, and the Republic of Korea's health security strategy. METHODS: This study employed a narrative review and policy analysis based on documents published between January 2025 and May 2026. Data were collected from official U.S. federal agency sources and major media outlets using specific search terms, including "Trump administration" and "public health policy." After screening for policy relevance and reliability, the reviewed literature was synthesized and qualitatively analyzed into four main topics: agency reorganization and budget cuts, immunization policy adjustments, data-driven research environments, and global health cooperation. RESULTS: To improve efficiency and realign priorities, the U.S. federal government restructured public health governance by streamlining U.S. Department of Health and Human Services agencies from 28 to 15 and reducing staff. Immunization policy shifted toward emphasizing individual choice, reducing the number of routine recommended vaccines from 17 to 11 by excluding rotavirus, hepatitis A and B, meningococcal, coronavirus disease 2019, and influenza vaccines. Multilateral cooperation also declined as the Centers for Disease Control and Prevention decentralized data management, the U.S. withdrew from the World Health Organization, and the United States Agency for International Development was dissolved, shifting the focus toward bilateral memoranda of understanding. However, these swift transformations triggered sharp institutional resistance, including judicial injunctions, government shutdowns, and state-level policy fragmentation. CONCLUSIONS: Alterations to these frameworks and guidelines may reduce the predictability of global infectious disease surveillance and cooperation. Consequently, the Korea Disease Control and Prevention Agency must enhance independent global surveillance, develop science-based communication to sustain vaccine confidence, and diversify multi- and bilateral cooperation networks to keep pace with evolving global health dynamics.