The National Institutes of Health said Thursday it is ending support for all research that makes use of human fetal tissue, eliminating funding for projects both within and outside of the agency.

A ban instituted in June 2019 by the first Trump administration ended all research done at the NIH and led to the rejection of most external grant proposals. It was lifted in 2021 by President Joe Biden, restoring financing and allowing scientists to conduct research using tissue from elective abortions to study and develop treatments for diseases.

Affects of Terminating the Funding

The new ban terminates support for all “grants, cooperative agreements, other transaction awards and research and development contracts,” according to an NIH statement.

“NIH will no longer support research using human tissue,” it said.

The agency did not immediately respond to a request for a comment and further clarification.

Human fetal tissue has been used to study cancer, AIDS, Parkinson’s disease, birth defects, blindness and other disorders, and to test new treatments and develop vaccines. Drugs used to treat rheumatoid arthritis, cystic fibrosis and hemophilia have been developed using human fetal tissue, and stem cells derived from the tissue are used to produce vaccines, including shots for rabies and hepatitis A.

In the statement released Thursday, the NIH noted that research supported by the agency that uses human fetal tissue has been declining since 2019. In its 2024 fiscal year, the NIH reported that it had allocated $53 million to 77 projects using human fetal tissue, a drop from the agency’s high of $115 million in 2018.

Dr. Jay Bhattacharya, the NIH director, said in a separate statement that the agency will look at making additional investments in “alternative, validated models” and emerging biotechnologies that could “reduce or potentially replace reliance on human embryonic stem cells.” Those include techniques that use computer and mathematical modeling to understand biological systems and organoids, mini-organs that can be grown in laboratories from specific patients’ cells and then used to study disease and treatment.

“NIH is pushing American biomedical science into the 21st century,” he said in the statement from the agency. “This decision is about advancing science by investing in breakthrough technologies more capable of modeling human health and disease.”

The Loss of Fetal Tissue Research

Projects involving fetal tissue that received funding in 2024 touched on a wide range of diseases, including viral infections, Type 1 diabetes, Gaucher disease, pediatric embryonic tumors and rhabdomyosarcoma, a rare cancer that affects soft tissue. More than a dozen studies were focused on various aspects of HIV.

Research that led to the development of monoclonal antibody treatments for COVID-19 relied on human fetal tissue, and many coronavirus vaccines financed by President Donald Trump’s Operation Warp Speed were tested in cells derived from fetal tissue.

Fetal tissue also has been used for decades to create so-called humanized mice. Since HIV can infect only human immune cells, the human fetal cells are injected into certain mice strains in order to create a functioning human immune system in the mice.

“Human fetal tissue research has been indispensable to biomedical progress and remains the gold standard for revealing how human cells and organs form,” said Tyler Lamb, director of policy for the International Society for Stem Cell Research.

He added, “Denying NIH-funded researchers access to human fetal tissue removes an irreplaceable scientific resource, slowing therapeutic innovation and delaying hope for patients and families living with devastating diseases.”

—

This article originally appeared in The New York Times.

By Roni Caryn Rabin
c.2026 The New York Times Company