A recently released report by the Institute of Medicine and National Research Council in the United States suggests that the National Institutes of Health (NIH) should dramatically curtail the use of chimpanzees as research subjects. According to the committee who put together the report, chimps should be used as subjects in biomedical research only under stringent conditions, including the absence of any other suitable model and inability to ethically perform the research on people.

While not perfect, this is a significant step forward in the struggle to protect the great apes from biomedical experimentation. As it stands, only two countries still use chimpanzees for research purposes, the United States and Gabon. The US maintains the largest colony in the world of more than 1,000 chimpanzees at six laboratories.

Most of the labs either conduct or make the chimps available for “invasive research”, which researchers define as “inoculation with an infectious agent, surgery or biopsy conducted for the sake of research and not for the sake of the chimpanzee, and/or drug testing.” Two federally funded US laboratories currently use chimps: Yerkes National Primate Research Center at Emory University in Atlanta, Georgia, and the Southwest National Primate Center in San Antonio, Texas. Five hundred chimps have been retired from laboratory use in the U.S. and live in sanctuaries in the U.S. or Canada.

In their report, the IMO goes on to state that use of chimps should be permissible only if forgoing their use will prevent or significantly hinder advances necessary to prevent or treat life-threatening or debilitating conditions.

They’re also recommending that the NIH limit the use of chimpanzees in behavioral research to studies that provide otherwise unattainable insights into normal and abnormal behavior, mental health, emotion, or cognition. The NIH should require such studies to be performed only on acquiescent animals using techniques that are minimally invasive and are applied in a manner that minimizes pain and distress. The report states that animals used in either biomedical or behavioral studies must be maintained in appropriate physical and social environments or in natural habitats.

“The committee concluded that research use of animals that are so closely related to humans should not proceed unless it offers insights not possible with other animal models and unless it is of sufficient scientific or health value to offset the moral costs. We found very few cases that satisfy these criteria,” said committee chair Jeffrey Kahn, senior faculty member, Johns Hopkins Berman Institute of Bioethics, Baltimore.

Essentially, the committee is suggesting that chimpanzees are not necessary for most biomedical research.

The committee acknowledged that advances in the development of other research tools and methods, including cell-based tests and other animal models, have rendered chimpanzees largely nonessential as research subjects. But it did acknowledge two possible ongoing uses: (1) the development of a limited number of monoclonal antibody therapies already in the pipeline, and (2) development of a vaccine that would prevent infection by hepatitis C virus (HCV).

According to the IMO:

New methods such as recombinant technologies can replace the chimpanzee in efforts to develop monoclonal antibodies. While industry and academic laboratories are in the process of adopting these alternate approaches, there may be a few therapies in development that require continued use of chimpanzees to keep progress from stalling and slowing patients’ access to needed new treatments. These cases should be assessed to ensure that they meet the criteria outlined in this report, and NIH should continue to support the development of and access to alternatives to make future use of chimpanzees unnecessary.

That said, the committee did not reach a consensus decision on whether chimpanzees are essential to the development of a prophylactic HCV vaccine and if or how much the use of chimpanzees would accelerate or improve this work.

The report admitted the possibility that chimpanzees may be needed in future research to develop treatments or preventive tools against as yet unknown diseases or disorders. It is difficult to say in advance whether other animal models or research tools will always serve effectively and quickly enough in the face of a novel health threat.

The committee focused on the scientific necessity of the chimpanzee as a research subject, but also take ethical issues into account. According to them, chimpanzees’ genetic closeness to humans and their similar biological and behavioral characteristics not only make chimpanzees a uniquely valuable species for certain types of research but also demand greater justification for conducting research with them.