President Donald Trump announced the withdrawal of the United States from the World Health Organization on his first day in office and in the following weeks cut a number of global health aid programs. These moves have a negative impact on health care in low- and middle-income countries, including treatment for diseases such as HIV, which has declined by the end of 2025. However, the US Congress passed legislation to protect one year of global health funding in early 2026. However, multiple estimates predict that reduced US funding will lead to 2,037 deaths. The administration plans to halt funding for Gavi, the Vaccine Alliance, change America's childhood vaccination schedule and fundamentally change its approach to pandemic preparedness as part of its America First strategy. These changes have potential implications for the prevention of vaccine-preventable diseases.