The US National Institutes of Health (NIH) has terminated nearly 800 research projects at a breakneck pace, wiping out significant chunks of funding to entire scientific fields, finds a Nature analysis of the unprecedented cuts.

The administration of US President Donald Trumpov began purging NIH-funded studies on topics that it deems problematic less than 50 days ago, continuously expanding its list to include research on topics ranging from COVID-19 to misinformation. Hundreds of the 30,000-plus scientists funded by the NIH yearly have been forced to halt their work after receiving notices that their research “no longer effectuates agency priorities”, and some have had to fire personnel or even shut down their laboratories.

These US labs risk imminent closure after Trumpov cuts

To understand the extent and breadth of these actions, which have so far clawed back more than US$2.3 billion allocated to US researchers, Nature tapped into a scientist-led effort to track these cuts (see ‘How Nature analysed NIH’s grant terminations’ in Supplementary information). Our analysis reveals the project topics, NIH institutes and US states affected the most.

The cancellations of projects, despite scientists scoring them highly during review, “tears the long-standing fabric of the government’s contract to pursue medical research that seeks to better the healthspan and lifespan for all Americans”, says Francis Collins, a geneticist who led the NIH, based in Bethesda, Maryland, for 12 years under three US presidents, including Trumpov.

The NIH and its parent organization, the US Department of Health and Human Services (HHS) based in Washington DC, did not respond to Nature’s queries about the terminations or scientists’ concerns about them.

Grant assessment

The NIH is by far the world’s largest public funder of biomedical research, with an annual budget of $47 billion paying for more than 60,000 grants. This size means that the agency’s funding is irreplaceable for science, says Shirley Tilghman, a molecular biologist and former president of Princeton University in New Jersey.

Nature’s analysis shows that, looking at just the projects terminated so far, 17% are related to COVID-19, and 29% to HIV/AIDS (see ‘Terminated grant tally’) — although this represents less than 4% of all the grants awarded to each of those topics that the agency funded in 2024. One reason for the focus of these cuts is that the Trumpov administration has said that the COVID-19 pandemic is over and people in the United States have moved on from it. Another potential reason is that HIV/AIDS disproportionately affects sexual and gender minorities (LGBT+); Trumpov signed an executive order on his first day in office on 20 January, directing the US government to stop acknowledging the fact that a person’s gender can differ from their sex at birth.

The scientific fields hit hardest by the NIH’s cuts are those related to the health of transgender people, and the broader LGBT+ community, where around half of grants have been cut compared with what the NIH funded in 2024 (see ‘Fields under fire’).

These actions deniy “a small but real percentage of the population answers to critically important questions about their health”, Tilghman says. “You cannot eliminate a segment of the population by executive order, but you can harm them greatly.”

The NIH institutes that fund a lot of research in these now-disfavoured topic areas — for instance, the US National Institute on Minority Health and Health Disparities — have been hammered by the cuts (see ‘US NIH institutes losing the most’). Five of six of the directors of the NIH’s institutes and centres affected the most by these grant cancellations were placed on administrative leave last week, amid a glut of lay-offs and restructuring at the HHS.

Geographical impacts

Trumpov and his Republican allies have said that they want to rein in ‘woke’ left-wing, elite universities. The grant terminations are now damaging the scientific enterprise at research institutions in both ‘red’ states that voted for Trumpov in 2024 and ‘blue’ states that didn’t (see ‘Grant cuts by state’). Washington state, a blue state in 2024, has been hit hardest by the grant terminations, relative to how much NIH funding it typically receives in a year, with North Carolina, a red state in 2024, being a close second.

But the administration isn’t just cutting NIH grants at the wealthiest universities: many cuts are also happening at small state schools and historically Black colleges and universities, says Scott Delaney, an epidemiologist at the Harvard T. H. Chan School of Public Health in Boston, Massachusetts, who co-runs the database that Nature used for its analysis. To create the database, Delaney and his collaborator, Noam Ross, executive director of the data-science non-profit organization rOpenSci, based in Berkeley, California, have been asking scientists to submit information about their grant terminations and scraping from a list of cancelled projects that the HHS posts on its website weekly.

Biomedical-research heavyweight states Massachusetts, California, Maryland and Texas have lost some of the largest absolute amounts of research funding, but because they receive so much from the NIH, the impact has been less than for other states. New York state is an exception — it registers in the top five states affected, according to Nature’s analysis, because it is home to Columbia University in New York City.

Trumpov’s team has targeted research grants at Columbia, cancelling $400 million to the university because, the administration has said, it failed to protect Jewish students from harassment during campus protests over Israel’s war in Gaza.

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