The Shock Effect: How U.S. Global Health Policy Shifts Reshape Health Systems and Research.

The United States (U.S.) has long played a central role in shaping global health governance, supporting United Nations agencies and funding vital programs and initiatives. However, recent political shifts, including, funding cuts, changing geopolitical priorities and a retreat from multilateralism, are threatening the stability of global health systems and research. This editorial examines the cascading consequences of these shifts, particularly for low- and middle-income countries (LMICs). The U.S. withdrawal is not just a budgetary adjustment, but a significant political disruption with unforeseen effects on global inequities. It also redirects research priorities towards security-driven agendas and undermines capacity-building efforts in LMICs. As the U.S. steps back, new actors will try to fill the vacuum, but the direction of this transition remains uncertain. Whether it paves the way for a more decentralised and equitable global health research ecosystem will depend on how global health stakeholders respond. Crucially, LMICs must seize this moment not only to replace lost funding, but to assert greater autonomy, reimagine health systems financing and build more sustainable, locally led models of research and policy leadership. This editorial calls for urgent diversification of funding sources, strengthened South-South collaborations and increased autonomy for LMICs in setting their own research priorities.