Given that chimpanzees are so closely related to us, American researchers should hardly ever allow them to be used in biomedical research, says a report from the Institute of Medicine and National Research Council. These include the absence of suitable models and inability to ethically perform the research on people.
In addition, these animals should be used only if forgoing their use will prevent or significantly hinder advances necessary to prevent or treat life-threatening or debilitating conditions. In short, chimpanzees are obsolete in most biomedical research.
The report attracted a huge amount of public attention and the committee was swamped with public comments and emails.
NIH also should 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 report says. They should be performed only on acquiescent animals using techniques that are minimally invasive and are applied in a manner that minimizes pain and distress.
Advances in the development of other research tools, including cell-based tests and other animal models, have rendered chimpanzees largely nonessential as research subjects, the committee noted. It acknowledged two possible ongoing uses: the development of a limited number of monoclonal antibody therapies already in the pipeline, and development of a vaccine that would prevent infection by hepatitis C virus (HCV).
The committee did not reach a consensus decision on whether chimpanzees are essential to the development of a prophylactic Hepatitis C vaccine and if or how much the use of chimpanzees would accelerate or improve this work. Roughly 3.2 million Americans are chronically infected with HCV, and about 17,000 new infections occur each year in the United States alone. Persistent infection can lead to liver disease and cancer; it is the most common cause of liver failure and transplantation in the United States.
Chimpanzees and humans are the only two species that are susceptible to HCV infection, and no other suitable animal models currently exist to test a prophylactic vaccine. However, chimpanzees' immune systems clear HCV from their bodies more effectively, and they are less likely to develop liver damage. The committee members agreed that it would be possible and ethical to test a prophylactic vaccine candidate in humans without prior testing in chimpanzees, provided that it was first shown to be safe and to stimulate an immune response in other animals. However, the committee was evenly split on the necessity of testing various HCV vaccine candidates in chimpanzees before proceeding to human trials.
The committee would not close the door on 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 impossible 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.
As of May this year, 937 chimpanzees, ranging in age from less than 1 year old to greater than 41, were available for biomedical and behavioral research in government and private labs. About 600 are owned or supported by the NIH. At the moment, the government has imposed a moratorium on breeding chimpanzees in captivity and it is illegal to import them. As a result, by 2037 the federally funded chimpanzee research population will “largely cease to exist” in the United States. ~ National Academy of Science, Dec 15; Science Insider, Dec 15