The National Institutes of Health has lost thousands of workers since President Donald Trump began his second term.
Among them: scientists who pioneered cancer treatments, researched tick-borne diseases, or worked to prevent tobacco use.
We spoke to a half dozen scientists who said they left the agency because of the tumult of 2025 and talked about the work they left behind. They say the exodus from the world’s largest public funder of biomedical research will harm the nation’s ability to respond to illness.
“People are going to get hurt,” said Sylvia Chou, a scientist who worked at the National Cancer Institute in Rockville, Maryland, for over 15 years before she left in January. “There’s going to be a lot more health challenges and even deaths, because we need science in order to help people get healthy.”
The NIH consists of 27 institutes and centers, each with a different focus. Major research areas include cancer; infectious diseases; aging-related diseases such as Alzheimer’s; heart, lung, and blood diseases; and general medicine.
Over decades, the value of the NIH may be the one thing everyone in Washington has agreed on. Lawmakers have routinely boosted its funding — even for this fiscal year, in defiance of the White House, which had proposed cutting the agency’s funding by 40%.
Our reporting showed that, nonetheless, the Trump administration’s actions to curb certain research and push out scientists perceived as disloyal are having far-reaching repercussions. The NIH workforce stands at about 17,100 people — its lowest level in at least two decades.
Scientists across specializations outlined challenges that made them decide to leave. They included delays in accessing research equipment and supplies, the termination of funds for topics the Trump administration deemed off-limits, and delayed or denied travel authorizations.
Even research aligned with the Trump administration’s stated priorities has suffered, they said. They questioned whether the NIH could continue to fulfill its mission to “enhance health, lengthen life, and reduce illness.”
“It’s clear when someone comes out with a drug and now you’ve just cured a disease. But you never know which ones could have been cured,” said Daniel Dulebohn, a researcher who spent nearly two decades at Rocky Mountain Laboratories in Hamilton, Montana. “We don’t know what we’ve lost.”
Dulebohn left the NIH’s infectious disease and allergy institute in September and is considering leaving the scientific field altogether.