Animal research: Why are we still using monkeys?

A common argument from animal rights organizations is that animal models cannot tell us anything useful about human medicine, that animal research is outdated, and should be replaced with other methods. But in a recent article, a group of leading scientists argues that “Primate models still matter” — with the right attention to the animals’ social needs and welfare.

The mantra of “Replace, Reduce, Refine” is a common place in the animal research community — with an emphasis on replacing animal models where possible. Yet while most research with vertebrates involves rodents and fish, non-human primates (principally rhesus monkeys) remain a vital model for studying many diseases and conditions. A recent article in the American Journal of Primatology sets out the issues around research with non-human primates.

Research involving nonhuman primates (NHPs) has played a vital role in many of the medical and scientific advances of the past century. NHPs are used because of their similarity to humans in physiology, neuroanatomy, reproduction, development, cognition, and social complexity-yet it is these very similarities that make the use of NHPs in biomedical research a considered decision. As primate researchers, we feel an obligation and responsibility to present the facts concerning why primates are used in various areas of biomedical research. Recent decisions in the United States, including the phasing out of chimpanzees in research by the National Institutes of Health and the pending closure of the New England Primate Research Center, illustrate to us the critical importance of conveying why continued research with primates is needed. Here, we review key areas in biomedicine where primate models have been, and continue to be, essential for advancing fundamental knowledge in biomedical and biological research

Kimberley Phillips of Trinity University, San Antonio, Texas and co-authors discuss how non-human primate models are ideal for studying heart and respiratory disease; reproduction and pharmacology; immunology and infectious disease, including vaccines and treatments for HIV/AIDS; behavior, cognition and neuroscience, among many other topics.

primate monkey animal testing
Image Credit: CNPRC/Speaking of Research

Primate and monkey models have contributed to the fight against polio, typhoid and yellow fever, and have made possible advances in treating heart disease, AIDS, cancer, diabetes, asthma, and malaria. Efforts are under way to develop treatments for emerging diseases such as Ebola and avian influenza, and conditions that becoming more common, for example Parkinson’s disease, Alzheimer’s, obesity, arthritis, infertility, and aging.

Nonhuman primates provide unique opportunities for scientists and physicians to study human disease, because while we have important differences, their biology is similar to ours in many ways. Yet this similarity also raises ethical issues, especially with the great apes, according to Phillips et al.

The recent decision by the National Institutes of Health to end support for some forms of invasive biomedical research with chimpanzees reflects the development, by scientists, of alternative models for some types of research as well as reflecting a collective desire to involve chimpanzees only in research that is either noninvasive or otherwise essential to scientific progress.

The use of these animals in research must be carefully considered and conducted in a controlled and thoughtful manner, the authors write. They advocate standards of care that consider not just food, housing and veterinary care, but pay attention to the animals’ cognitive, social and psychological needs.

“Efforts are now made to enhance psychological well‐ being through social housing, addressing the specific social and development needs of infants and aged individuals, and providing environmental enrichment,” they write.

“We are at a critical crossroads in our society and unless NHP research is given the philosophical, emotional, and financial support and infrastructure that is needed to sustain it and grow, we are in danger of losing irreplaceable unique models and thus, our ability to continue to explore and understand, and develop preventions and treatments for numerous conditions that inflict great suffering on humans.”

Andy Fell

To learn more about the role of animal research in advancing human and veterinary medicine, and the threat posed to this progress by the animal rights lobby, follow us on Facebook or Twitter.