SAN ANTONIO — BIOMEDICAL research with captive chimpanzees, an enterprise that has helped save millions of human lives, is being dismantled. The National Institutes of Health, citing a reduced need for chimps in research as well as their “likeness to humans,” recently decreed that all but 50 of the 451 chimps that are federally owned or supported will be retired and moved to sanctuaries.

As the chief scientific officer at a research institute that has 90 chimps supported by the N.I.H., I bemoan this development. In my view, the benefits of such research outweigh the costs. Many people disagree with me, citing their commitment to animal welfare.

But here is a fact about animal welfare that my opponents fail to consider: research with captive chimpanzees is vital to the development and testing of vaccines that can help save the lives not just of humans but also of wild chimpanzees and gorillas. It could even help those species from becoming extinct.

Wild great ape populations are being decimated by diseases. Over the last 20 years, Ebola hemorrhagic fever has killed a third of the wild gorilla population and nearly as high a fraction of the wild chimpanzee population. Of the chimps in Gombe Stream National Park, in Tanzania, more than 40 percent are affected by chimpanzee AIDS; their death rate is 10 to 16 times higher than that of uninfected chimps. Human respiratory diseases, which are transferred to great apes in areas where they have close contact with people, are the most destructive: 48 percent of all recorded disease-related deaths at Gombe from 1960 to 2006 were from respiratory illness.