We should have much more stringent rules regarding the use of chimps, our closest relatives on this planet, says a new report issued by the Institute of Medicine (IOM) and the National Research Council. Chimpanzees and humans share a surprising number of behavioral traits, the authors added. Using them in animal experiments should only be done if there is absolutely no other choice – and even then, under much stricter conditions.

If foregoing an experiment with chimps means preventing or considerably undermining necessary breakthroughs to treat or prevent life-threatening or extremely debilitating human conditions, and there is no ethical way of carrying out human trials, then, and only then should they be considered, the authors emphasized.

The authors added that based on these criteria, in the vast majority of cases, chimpanzees are not needed for biomedical experiments.

The report also advises the National Institutes of Health that in behavioral research, chimpanzees should only be considered if there is no other way of obtaining insights into abnormal/normal behavior, emotion, mental health, or cognition.

When there is no alternative to using chimpanzees, experiments should only be done on compliant (acquiescent) animals, and researchers should only consider minimally invasive techniques that are administered in a painless and non-distressing way. Care should be taken to make sure the animal’s environment is comfortable and suitable.

Committee chair Jeffrey Kahn, senior faculty member, Johns Hopkins Berman Institute of Bioethics, Baltimore, said:

“The report’s recommendations answer the need for a uniform set of criteria for assessing the scientific necessity of chimpanzees in biomedical, comparative genomics, and behavioral research.

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.”

Scientific and technical advances have reached a point where the need to use chimpanzees has become scarce. Examples include cell based tests.

The authors mentioned two situations in which chimpanzees may still be needed:

  • Some monoclonal antibody therapy research which is already ongoing
  • The development of a hepatitis C virus (HCV) infection vaccine

Chimpanzees can be replaced by recombinant technologies in other monoclonal antibody research. In some cases, researchers should be given some time to adopt alternative approaches. In such cases, authorities should make sure the criteria outlined in the new report are met.

The authors emphasize that the NIH should carry on supporting the development of alternatives which eliminate the need to use chimpanzees.

No consensus was reached regarding the need for chimpanzees in current HCV vaccine development. The committee was not able to agree on whether using these animals would improve or speed up this work.

Approximately 3.2 million Americans have chronic HCV infection. 17,000 new HCV infection diagnoses are made in the USA each year. Chronic HCV infection significantly raises the risk of liver disease and cancer. The majority of liver transplant candidates in the USA are chronically infected with HCV. HCV is the most common cause of liver failure.

Only two animals are susceptible to HCV infection – humans and chimpanzees. In order to test a prophylactic vaccine, no other animal is possible. Humans clear HCV from their bodies less effectively than chimpanzees, and are more likely to develop liver damage (than chimps).

In a communique, the IOM wrote:

“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.”

Studies that focus on the development of an HCV vaccine which boosts the immune systems of already infected humans can be carried out without using chimpanzees, the committee agreed. This is also the case for antiviral medications for chronic HCV infected patients. As these products can be tested on humans, their development is going ahead without using chimpanzees.

The IOM wrote:

“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.”

Chimpanzees are genetically the most similar animals to humans; their biological and behavioral characteristics are also comparable to ours. These facts not only make them uniquely useful for some types of research, but also justify their use in research in some cases.

Written by Christian Nordqvist