FAQs Concerning the NIH Response to the IOM Report (2011) on the Use of Chimpanzees in Biomedical and Behavioral Research in NIH-Supported Research


1. Why did the IOM conduct the study to assess the current and future use of chimpanzees in research?

While used very selectively and in limited numbers for medical research, chimpanzees have served an important role in advancing human health in the past. Recent advancements in alternative research models, however, have made it necessary to reconsider the extent to which the chimpanzee model is needed. With support from members of Congress, the NIH in December 2010 requested that the Institute of Medicine (IOM), in collaboration with the National Research Council, undertake a study to review and assess the current and anticipated use of chimpanzees Exit Disclaimer in biomedical and behavioral research relevant to the mission of NIH. The NIH’s statement on the completed IOM study can be found in a December 2011 press release.

2. What are the main conclusions of the IOM report on the use of chimpanzees in research?

The IOM concluded that:

  • The use of chimpanzees in current and future research should be guided by a set of principles and criteria.
  • Based on these principles and criteria, most current use of chimpanzees for biomedical research is unnecessary.
  • However, the following research areas may continue to require the use of chimpanzees at this time:
    • a limited number of ongoing studies on monoclonal antibody therapies, but not for future monoclonal antibody research
    • research on comparative genomics
    • non-invasive studies of social and behavioral factors that affect the development, prevention, or treatment of disease
  • The committee was evenly divided on the necessity of the chimpanzee for the development of prophylactic hepatitis C virus vaccine.
  • NIH should continue development of non-chimpanzee models and technologies.
  • New, emerging, or re-emerging infectious diseases may present challenges that defy non-chimpanzee models and therefore, may require that chimpanzees be used in future research.

3. What are the guiding principles for the future use of chimpanzees in biomedical research, as defined by the IOM committee?

  1. The knowledge gained must be necessary to advance the public’s health.

  2. There must be no other research model by which the knowledge could be obtained, and the research cannot be ethically performed on human subjects.

  3. The animals used in the proposed research must be maintained either in ethologically appropriate physical and social environments or in natural habitats.

4. What recommendations were made by the IOM committee?

Recommendation 1: The NIH should limit the use of chimpanzees in biomedical research to those studies that meet the following three criteria:

  1. There is no other suitable model available, such as in vitro, non-human in vivo, or other models, for the research in question;

  2. The research in question cannot be performed ethically on human subjects; and

  3. Forgoing the use of chimpanzees for the research in question will significantly slow or prevent important advancements to prevent, control, and/or treat life-threatening or debilitating conditions.

Animals used in the proposed research must be maintained either in ethologically appropriate physical and social environments (i.e., as would occur in their natural environment) or in natural habitats. Biomedical research using stored samples is exempt from the criteria.

Recommendation 2: The NIH should limit the use of chimpanzees in comparative genomics and behavioral research to those studies that meet the following two criteria:

  1. Studies provide otherwise unattainable insight into comparative genomics, normal and abnormal behavior, mental health, emotion, or cognition; and

  2. All experiments are performed on acquiescent animals, using techniques that are minimally invasive, and in a manner that minimizes pain and distress. Examples of how the IOM defined “acquiescence” and “minimally invasive” are provided on page 34 of the IOM      report.

Animals used in the proposed research must be maintained either in ethologically appropriate physical and social environments (i.e., as would occur in their natural environment) or in natural habitats. Comparative genomics and behavioral research using stored samples are exempt from these criteria.

5. Does NIH agree with the IOM report?

NIH has considered the report carefully and accepts the IOM’s recommendations. NIH is in the process of developing a complete plan for implementation of the IOM’s guiding principles and criteria. 

6. What benefits have been derived from the use of chimpanzees in research?

Examples of some of the benefits include:

  • Contributing to the development of the hepatitis A and B vaccines that are in use today. These vaccines most often are given as pediatric immunizations. Since 1991, there has been a 98 percent decline in hepatitis B in children under the age of 15 years. The rate of new hepatitis A infections in the United States declined by more than 92 percent between 1995 and 2008.
  • Determining that dietary salt is a major causative factor of elevated blood pressure (Denton et al., 1995).
  • Contributing to our understanding of the sequence of menopause.
  • Developing FDA-approved monoclonal antibodies for use in treating lymphomas and other cancers, and establishing that in vitro differentiated dendritic cells can serve as vehicles for cancer immunotherapy (Larsson et al., 2004).

7. Will the Federal Government save money if the NIH removes chimpanzees from activeresearch?

No. The cost of caring for the chimpanzees is not expected to decrease if animals are removed from active research. Many facilities earn research income, which helps to offset the cost of caring for and housing chimpanzees. If animals are removed from active research, costs will likely increase because the cost of care will no longer be offset by research income earned by the research facilities. Cost, however, is not a factor in determining which current research involving chimpanzees meets the IOM principles and guidelines.

8. What alternative animal models are available today in biomedical research?

Several alternatives to chimpanzees are considered valid today. For example, various cell, tissue culture, and mouse models are available and used today for the study of hepatitis C virus (HCV) biology and some limited host/virus interactions. However, until a viable alternative is developed for evaluating vaccines against HCV, it is possible that the chimpanzee model will continue to be used if the research meets the IOM principles and criteria. HIV/AIDS research, once performed in chimpanzees, is now largely performed using monkeys, whose immune systems react to HIV-like infection in a way that more closely resembles human HIV infection.

9. How might biomedical research questions change in the future to necessitate or obviate the use of chimpanzees?

As science and technology evolve, the ability to ethically obtain disease-related information directly from humans also may evolve, further decreasing reliance on chimpanzees. Conversely, new, emerging, or re-emerging infectious diseases may trigger an unforeseen need for the chimpanzee model.

10. What are some examples of NIH-funded research into alternatives that might supplement or replace the use of chimpanzees in research?

There has been some progress in the development of cell lines and mouse models to replicate human biology. These include the development of Huh 7 cell lines for investigating the cellular determinants of hepatitis C virus (HCV)¹, human liver chimera mice for investigating infection and treatment of hepatitis B and C viruses ², and genetically humanized mouse models for HCV infection ³ . These are important and continuing steps toward recreating—in the mouse—the human condition of HCV disease. Monkey models using the simian immunodeficiency virus (SIV) have replaced chimpanzee models for studies of HIV/AIDS pathogenesis and in the development of HIV vaccines and microbicides.

11. Will privately owned chimpanzees be subjected to the same guidelines set out by the IOM and accepted by the NIH?

All chimpanzees used for NIH-supported research will be subject to the IOM principles and criteria that have been accepted by the NIH. Both the NIH Office of Laboratory Animal Welfare and the U.S. Department of Agriculture (USDA) have compliance oversight responsibility involving animal welfare for Public Health Service (PHS) funded activities with chimpanzees, whether privately owned or federally owned. Privately owned animals used in non-PHS funded research would be under the exclusive oversight of the USDA at the federal level.

1 Lindenbach BD, Evans MJ, Syder,AJ, Wolk B, Tellinghuisen TL, et. al. (2005). Complete replication of hepatitis C virus in cell culture. Science. 309(5734):623-6.

2 Bissig KD, Wieland SF, Tran P, Isogawa M, Le TT, et. al. 2010). Human liver chimeric mice provide a model for hepatitis B and C virus infection and treatment. J Clin Invest. 120(3):924-30.

3 Dorner M, Horwitz JA, Barry WT, Feng Q, Mu K, et. al. (2011). A genetically humanized mouse model hepatitis C virus infection. Nature. 474(7350):208-11. 

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