On May 1, 2025, the U.S. National Institutes of Health (NIH), the world’s largest funder of biomedical research, announced that by October, it will cease funding research outside the United States, imperiling thousands of global-health projects and clinical trials on topics such as emerging infectious diseases and cancer.

The NIH will not renew or issue new ‘foreign subawards’, which are NIH funds that a U.S. researcher can give to an international collaborator to help complete a project. The agency typically spends about US $500 million on these awards each year.

The announcement states that the agency is establishing a new award structure for foreign researchers, which has not yet been released. The document cites national security and a lack of transparency as the rationale for the change.

“These decisions will have tragic consequences,” says Francis Collins, a geneticist who led the NIH, based in Bethesda, Maryland, for 12 years under three US presidents. As part of its effort to reduce federal spending, the administration of President Donald Trump has already effectively shuttered the US Agency for International Development, which funded research, prevention and care for diseases worldwide.

“Disease outbreaks that start anywhere in the world can reach our shores in hours,” Collins says. “To just pull the plug is short-sighted and self-defeating.” If the United States pulled back all of its global health funding — which was US$12 billion in 2024 — roughly 25 million people could die in the next 15 years, according to models.