Responding to Kaitlin R. Weed’s “Humanity and Inhumanity of Nonhuman Primate Research” in the September 2024 issue of the journal, we argue that, contra the author’s claim, use of nonhuman primates (NHPs) and other animals is unjustified and highlight reasons for growing opposition to using NHPs in biomedical or behavioral experimentation, testing, or research.
While the presence of NHPs and other animals in past research arguably was valid, their necessity in research—especially now—is not.1 Despite the use of NHPs in research, approximately 95% of new drugs fail in clinical trials.2 In 2019, 99% of Alzheimer’s disease (AD) research trials showed no difference between the intervention drug and placebo.3 Despite recent (but controversial) advancements4,5—specifically, the approval of several monoclonal antibody therapies—major discord continues to surround the models used to mimic current theories of AD etiology and pathology, prompting greater scrutiny of preclinical animal models.6 Moreover, of hundreds of HIV vaccines developed and tested in NHPs, none are approved for humans.7,8
Despite strong insistence from some researchers that halting chimpanzee use in research would stall clinical progress,9 in 2011 the Institute of Medicine Committee on the Use of Chimpanzees in Biomedical and Behavioral Research concluded that most experimental uses of chimpanzees were unnecessary.10 Poor translation of conclusions drawn from research on other animals to humans, combined with the increasing availability of non-animal methods, has generated a scientific landscape that is continuing to move away from animal use, as demonstrated by the implementation of the US Food and Drug Administration’s (FDA’s) New Alternative Methods Program11 and the adoption in 2023 of the FDA Modernization Act 2.0.12 The aforementioned legislation gives the FDA the statutory authority to consider preclinical testing performed using non-animal methods, meaning animal tests are not required before drugs are advanced to human trials.12
Opposition to research on NHPs has merit. The Silver Spring Monkeys case mentioned in Weed’s article resulted in changes to laws intended to improve care of laboratory-based animals, but some facilities that use primates still fail to uphold minimal standards of the Animal Welfare Act, resulting in some NHPs being denied veterinary care13 and sustaining injuries14 or dying15 due to improper handling, monitoring, or facility maintenance. Moreover, removal of primates from their native habitats threatens wild populations,16 and transporting these NHPs to laboratories risks transmission of zoonotic diseases (which can also confound data collected from infected animals).17
The depiction of a content rhesus macaque in Weed’s article offers a misleading view of NHPs in research, obscuring the reality that they suffer when they are denied dignity, respect, and opportunities to live their lives in their native habitats on their own terms. It’s time we stopped thinking of NHP research as something of value and recognize it for what it is: a practice that future generations will—especially if current trends of using fewer NHPs in research continue—likely look back on with incredulity and regret.
References
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Matthews RAJ. Medical progress depends on animal models—doesn’t it? J R Soc Med. 2008;101(2):95-98.
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National Center for Advancing Translational Sciences. About new therapeutic uses. National Institutes of Health. Updated April 19, 2024. Accessed September 25, 2024. https://ncats.nih.gov/research/research-activities/ntu
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Cummings J, Feldman HH, Scheltens P. The “rights” of precision drug development for Alzheimer’s disease. Alzheimers Res Ther. 2019;11(1):76.
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Nelson SE, Lopez OL. Lecanemab for Alzheimer disease: is it worth it? Neurology. 2024;102(7):e209265.
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Meeting highlights from the Committee for Medicinal Products for Human Use (CHMP) 22-25 July 2024. European Medicines Agency. July 26, 2024. Accessed October 15, 2024. https://www.ema.europa.eu/en/news/meeting-highlights-committee-medicinal-products-human-use-chmp-22-25-july-2024
- Cummings JL. Translational scoring of candidate treatments for Alzheimer’s disease: a systematic approach. Dement Geriatr Cogn Disord. 2020;49(1):22-37.
- Bailey J. An assessment of the role of chimpanzees in AIDS vaccine research. Altern Lab Anim. 2008;36(4):381-428.
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Kwon D. HIV: how close are we to a vaccine—or a cure? Nature. Published online September 2, 2024.
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Great ape debate. Nature. 2011;474(7351):252-252.
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Altevogt BM, Pankevich DE, Shelton-Davenport MK, Kahn JP, eds; Institute of Medicine; National Research Council. Chimpanzees in Biomedical and Behavioral Research: Assessing the Necessity. National Academies Press; 2011.
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New Alternative Methods Subcommittee. Potential approaches to drive future integration of new alternative methods for regulatory decision-making. US Food and Drug Administration; 2024. Accessed October 16, 2024. https://www.fda.gov/media/182478/download
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Zushin PH, Mukherjee S, Wu JC. FDA Modernization Act 2.0: transitioning beyond animal models with human cells, organoids, and AI/ML-based approaches. J Clin Invest. 2023;133(21):e175824.
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Animal and Plant Health Inspection Service. University of Utah inspection report. US Department of Agriculture; 2020. Accessed September 25, 2024. https://arlo.riseforanimals.org/records/21329
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Animal and Plant Health Inspection Service. University of Wisconsin-Madison inspection report. US Department of Agriculture; 2022. Accessed September 25, 2024. https://arlo.riseforanimals.org/entity/university-of-wisconsin-madison-1551/records/26723
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Animal and Plant Health Inspection Service. Emory University inspection report. US Department of Agriculture; 2023. Accessed September 25, 2024. https://arlo.riseforanimals.org/records/31901
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Gamalo LE, Ilham K, Jones-Engel L, et al. Removal from the wild endangers the once widespread long-tailed macaque. Am J Primatol. 2024;86(3):e23547.
- Conroy G. How wild monkeys “laundered” for science could undermine research. Nature. 2023;623(7988):672-673.