The Trump administration has dealt a sharp blow to work on H.I.V. vaccines, terminating a $258 million program whose work was instrumental to the search for a vaccine.

Officials from the H.I.V. division of the National Institutes of Health delivered the news on Friday to the program’s two leaders, at Duke University and the Scripps Research Institute.

Both teams were collaborating with numerous other research partners. The work was broadly applicable to a wide range of treatments for other illnesses, from Covid drugs to snake antivenom and therapies for autoimmune diseases.

“The consortia for H.I.V./AIDS vaccine development and immunology was reviewed by N.I.H. leadership, which does not support it moving forward,” said a senior official at the agency who was not authorized to speak on the matter and asked not to be identified.

“N.I.H. expects to be shifting its focus toward using currently available approaches to eliminate H.I.V./AIDS,” the official said.

The program’s elimination is the latest in a series of cuts to H.I.V.-related initiatives, and to prevention of the disease in particular. Separately, the N.I.H. also paused funding for a clinical trial of an H.I.V. vaccine made by Moderna.