The Trump administration stormed into office, loudly firing workers and closing diversity programs. But behind the scenes, it has also brought biomedical research to the brink of crisis by holding up much of the $47 billion the United States spends on the field every year.

The world’s leading medical labs can be found in the United States, and they rely on grants from the National Institutes of Health. The agency has stopped vetting future studies on cancer, Alzheimer’s, heart disease and other ailments. Trump aides have said they just need time to review spending their predecessors had promised, but it’s unclear what they’re looking for at the N.I.H. or when scholars can expect to start receiving money again.

In today’s newsletter, I’ll walk you through what happened — and why it matters.

A complex machine

Late last month, when the Trump administration froze government grants, a federal judge said it couldn’t just hold back money Congress had agreed to spend. But spending money at the N.I.H., which awards more than 60,000 grants per year, isn’t so simple.

That’s because new grants endure a tortured bureaucratic process. The agency has to notify the public of grant review meetings in The Federal Register, a government publication. Then scientists and N.I.H. officials meet to discuss the proposals. The problem is that the Trump administration banned those announcements “indefinitely.” So new research projects can’t get approved.

In effect, scientists say, the Trump administration is circumventing the court order. Health officials didn’t block research outright, but by shutting down the process, they’re still not spending much of the money Congress allocated to various research goals.

The administration has also proposed other big changes, saying that universities should bear more of the “indirect costs” of research: maintaining lab space, paying support staff. Trump aides say the changes would trim administrative bloat and free up more government money for research.

Labs hit pause

Scientists are panicked, and hundreds of studies are at a standstill, including ones on pancreatic cancer, brain injuries and child health. Last week alone, the N.I.H. canceled 42 of 47 scheduled meetings to assess new grants. Some examples of stalled projects:

• For years, Steffanie Strathdee at the University of California San Diego has followed drug users to research overdoses, which kill some 100,000 people in the United States each year. Her investigation of H.I.V. infections in that group was ready to begin — but came to an abrupt halt when the N.I.H. canceled a review panel meeting this month. “Everything is absolutely frozen,” she told me. “It’ll just sit there, hanging in limbo.”

• Anthony Richardson at the University of Pittsburgh was expecting a review panel to weigh a grant application of his on staph infections in people with diabetes, a disease that afflicts more than one-tenth of Americans. It never happened. “I am not 100 percent sure what their motives are,” he said.

In response to all the uncertainty, universities are retrenching. The University of Pittsburgh froze Ph.D. admissions. Columbia University’s medical school paused hiring and spending. The Massachusetts Institute of Technology froze the hiring of nonfaculty employees.

Some lab leaders told me they were making contingency plans to fire scientists. Graduate students are searching for new sources of funding.

What next?

It’s hard to say how long the holdup will last. The Trump administration hasn’t submitted a single new grant review meeting to The Federal Register since a day after it took office. And even if it started adding new ones, the agency traditionally gives several weeks’ notice.

At risk are not only the tens of thousands of grants the N.I.H. awards each year, but also American dominance of biomedical research. Every dollar the agency spends on research generates more than two dollars in economic activity, the N.I.H. has said. Scores of patents follow. By some measures, the United States produces more influential health-sciences research than the next 10 leading countries combined.

The science unfolds across the country, including in red states, where lawmakers have complained about proposed changes to indirect costs.

Those findings often fuel pharmaceutical advancements, laying a foundation for drugs and vaccines long before private funders see such work as worth investing in.

Even Ozempic traces its roots back in part to work at the N.I.H on animal venom. Scientists found that the toxin from Gila monster lizards seemed to have particular physiological effects, helping lead eventually to one of the world’s most profitable and promising drugs.

New advances like those, scientists say, are in danger.

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