National Institutes of Health officials have urged scientists to remove all references to mRNA vaccine technology from their grant applications, two researchers said, in a move that signaled the agency might abandon a promising field of medical research.

The mRNA technology is under study at the NIH for prevention and treatment of infectious diseases, including flu and AIDS, and also cancer. It was deployed in the development of covid-19 vaccines credited with saving 3 million lives in the U.S. alone — an accomplishment President Donald Trump bragged about in his first term.

A scientist at a biomedical research center in Philadelphia wrote to a colleague, in an email reviewed by KFF Health News, that a project officer at NIH had “flagged our pending grant as having an mRNA vaccine component.”

“It’s still unclear whether mRNA vaccine grants will be canceled,” the scientist added.

NIH officials also told a senior NIH-funded vaccine scientist in New York state, who does not conduct mRNA vaccine research but described its efficacy in previous grant applications, that all references to mRNA vaccines should be scrubbed from future applications.

Scientists relayed their experiences on the condition of anonymity for fear of professional retaliation by the Trump administration.

A senior official at the National Cancer Institute confirmed that NIH acting Director Matthew Memoli sent an email across the NIH instructing that any grants, contracts, or collaborations involving mRNA vaccines be reported up the chain to Health and Human Services Secretary Robert F. Kennedy Jr.’s office and the White House.

Memoli sent a similar message ahead of the agency canceling other research, such as studies of vaccine hesitancy.

Memoli’s email on that topic bluntly stated that NIH was not interested in learning why people shun vaccines or in exploring ways to “improve vaccine interest and commitment.”

The National Cancer Institute official, who also spoke on the condition of anonymity for fear of reprisals, said that “it is reasonable to assume mRNA vaccine work is next.”

The official said a similar memo also went out regarding NIH-funded work in South Africa, which the White House has targeted over false claims that the country’s government is persecuting white people. More recently, another one went out regarding all global research collaborations, the official said.

Spokespeople for the White House, HHS, and the NIH did not respond to requests for comment.

The NIH, whose latest annual budget was $47 billion, is one of the world’s most critical sources of funding for basic biomedical research. Its mission and programs are under unprecedented scrutiny from Trump’s White House and the Department of Government Efficiency, the Elon Musk-led agency created by a Trump executive order that has directed federal agencies to prepare for widespread layoffs.

The NIH is funding at least 130 studies involving the mRNA technology in covid vaccines produced by Pfizer-BioNTech and Moderna that have been administered to billions of people worldwide.

A former government official familiar with internal discussions said that the Trump administration intends to cut some grants for mRNA vaccine research but that the timing is unclear. The person spoke on the condition of anonymity to protect relationships with the administration.

Political conservatives in the U.S. have promulgated conspiracy theories, unsupported by scientific evidence, that the shots and their relatively new technology are dangerous. This has undermined public support for covid vaccinations and mRNA research.

“There will not be any research funded by NIH on mRNA vaccines,” the scientist in New York said in an interview. “MAGA people are convinced that these vaccines have killed and maimed tens of thousands of people. It’s not true, but they believe that.”

Meanwhile, hundreds of other vaccine-related studies are in limbo. Kawsar Talaat, a vaccine researcher at the Bloomberg School of Public Health at Johns Hopkins University, has been waiting since the fall for money needed to recruit subjects for a study of an antidiarrheal vaccine.

“NIH approved our funding,” she said, “and now we’re waiting, and we don’t know if it’s going forward or going to be killed.”

The scientist in Philadelphia signaled that he believes Kennedy, a longtime anti-vaccine activist, is responsible for the NIH’s turn against mRNA research.

“Kennedy’s war on vaccines has started,” the scientist told his colleague.

The scientist in New York said that it was “ridiculous” to remove mRNA language from the grant applications. But “if my grant is rejected for any reason,” the scientist said, “people in my lab will lose their jobs.”

“I’ve worked with some of them for 20 years,” the scientist added. “They have children and families. There is a real climate of fear in academia about this now, especially among vaccine scientists.”

“My grant does not involve a request for funds to conduct mRNA vaccine experiments,” the scientist said, “so my principal concern was to avoid word-search flags that, at minimum, would lead to delays in any funding.”

While tenured research professors at universities generally receive a salary from their institution, the staffers who work in their labs and offices are often paid through NIH grants. The 2023 Nobel Prize in physiology or medicine was given to two scientists for developing mRNA vaccines, through work that relied on pharmaceutical companies and on NIH scientists working under infectious disease specialist Anthony Fauci.

According to Sen. Bill Cassidy, a Louisiana Republican who chairs the chamber’s Health, Education, Labor and Pensions Committee, Kennedy promised during his Senate confirmation process that he would protect “the public health benefit of vaccination” and “work within the current vaccine approval and safety monitoring systems, and not establish parallel systems.”

Cassidy, a physician, had expressed reservations about confirming Kennedy to the HHS post and challenged his anti-vaccine views during a confirmation hearing. He ended up voting for him, he said, because Kennedy had agreed to work closely with Cassidy and his committee.

However, Kennedy has faced scrutiny in his first weeks in office for his handling of a large measles outbreak among mostly unvaccinated people in Texas that has led to the death of a child, the first U.S. measles death in more than a decade. A patient who tested positive for measles died in New Mexico, but the cause hasn’t been confirmed. Instead of urging vaccination against the disease, an almost surefire way to prevent infection, Kennedy has blamed malnourishment for the outbreak, promoted unproven treatments for measles, and falsely claimed in one Fox News interview that the vaccine is ineffective and even dangerous.

Cassidy did not respond to a request for comment on the NIH’s potential abandonment of mRNA vaccine research.

As part of the Trump administration’s push to examine spending on mRNA vaccines, health officials are reviewing a $590 million contract for bird flu shots that the Biden administration awarded to Moderna, Bloomberg News has reported. Legislation introduced by GOP lawmakers in at least seven states is aimed at banning or limiting mRNA vaccines. In some cases, the measures would hit doctors who give the injections with criminal penalties, fines, and the possible revocation of their licenses.

This article was reprinted from khn.org, a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF – the independent source for health policy research, polling, and journalism.