Could lab monkeys soon become a thing of the past?

The Trump administration’s scientific agenda has been widely characterized — rightly so — as a war on scientific progress. But, hear me out here: There is more to the story. 

This administration’s science policy is being shaped not solely by anti-science ideologues, but also by a motley coalition of players who have distinct criticisms of the status quo and are united by their willingness to part ways with established orthodoxies. They include animal advocates, some of them scientists themselves, who quite reasonably hope to advance science beyond its current dependence on animal experimentation. 

Research animals — from mice, to rabbits, to monkeys — still underpin much of medical research. But their usefulness as models for humans has always been limited. As Harvard bioengineer Don Ingber told me last year, “Everyone admits that animal models are suboptimal at best, and highly inaccurate more commonly.” The ethical problems with experimenting on animals are also immense, and meanwhile, a new generation of animal-free research technologies is proliferating, including lab-made organoids, organs-on-chips, and advanced computational modeling. 

Following on this line of reasoning, the National Institutes of Health (NIH), chief underwriter of university biomedical research in the US, last year under the leadership of director Jay Bhattacharya announced its intent to prioritize animal-free methods and reduce the use of animals in the science it funds. And, together with a major US biomedical research university, it just took a major step toward that goal. 

This week, the board of Oregon Health and Science University (OHSU), which runs the one of nation’s largest university centers for biomedical research on primates, voted unanimously to begin negotiating with the NIH about the agency’s proposal to end experiments on the primates and turn the center into a sanctuary for the animals. Many opponents of animal research hope this can create momentum for a phaseout of experimentation on our primate cousins.

A primate center under pressure  

OHSU’s primate research center, one of seven such federally funded centers still running at universities across the country, houses about 5,000 monkeys of various species — about 5 percent of all research monkeys in the US — including rhesus macaques, Japanese macaques, baboons, and squirrel monkeys. As part of the resolution reached this week, the center will stop breeding new monkeys, except as required by current experiments, while it discusses a potential plan with the NIH over the next six months to evolve from a primate breeder and experimentation facility to a sanctuary. 

OHSU has been dogged by controversy over conditions for animals there, including dozens of citations for violations of federal animal welfare law over the past few decades. Two monkeys died in 2020 after a worker accidentally placed them in a cage-washing machine, while, in 2023, a newborn monkey was killed after being hit by a falling sliding door, to name a couple examples. 

“[OHSU’s] record is one of the worst I’ve seen,” Delcianna Winders, a professor and director of Vermont Law and Graduate School’s Animal Law and Policy Institute, told me. “They just have negligent death after negligent death.” (Disclosure: In 2022, I attended a media fellowship program at Vermont Law and Graduate School.)

At a public meeting on Monday, researchers at the university’s primate center, along with others from the university and members of the general public, fiercely debated the proposal to end research at the center. “Past research in primates might have contributed to the advancement of medicine, but it is evident that the advanced methods now available have rendered it virtually obsolete,” said Michael Metzler, an emergency physician at Pioneer Memorial Hospital in Oregon. “These monkey studies divert funds and attention from the more valuable human-centered studies.”

Supporters of the primate center, meanwhile, condemned the university’s “immediate surrender to a hostile administration over political pressure,” as Cole Baker, a PhD student in biomedical engineering at OHSU, put it at the hearing. 

OHSU is no doubt under pressure to cooperate with the NIH, which, as of fiscal year 2023, provided the majority of the university’s research funding, and the White House has shown that it’s perfectly willing to punish universities that don’t comply with its wishes. But calls to close the center predate the Trump administration, and it is hardly just a Republican priority. Oregon’s Democratic governor Tina Kotek has urged the primate center’s closure, citing the example of Harvard University, which closed its own primate research center in 2015 amid controversy over its treatment of monkeys. 

Harvard’s decision itself is a noteworthy signal of where medical research is headed. One of the world’s top biomedical research institutions apparently determined — more than a decade ago — that the medical science coming from its primate research center wasn’t worth its continued financial, reputational, and ethical costs.

Why do we experiment on primates at all?

Debates over the necessity of primate research can be hard to parse. Advocates on either side of the question appear to be speaking different languages, with opponents arguing that animal data tells us very little that’s applicable to humans, and proponents insisting that they couldn’t possibly conduct research into debilitating human diseases without using monkeys. 

Thomas Kuhn, the 20th-century historian of science who coined the phrase “paradigm shift,” had a name for such breakdowns in communication: incommensurability. Scientists working within different paradigms can see the same thing and come to radically different conclusions because they are looking at problems through different conceptual lenses.

And scientists are still often siloed, as neuroscientist and Vox contributor Garet Lahvis, a former professor at OHSU who spoke in favor of ending research at the primate center at the hearing this week, pointed out to me. Primates are used in a wide range of research applications, including infectious diseases, neuroscience, psychology, reproductive health, and more, and that very specialization, he pointed out, can make it hard for scientists to take a broader scientific perspective.

Primate research, like most things in science, is the product of path dependency and historical circumstance. In the 1960s, the US created a system of federally funded primate centers, like the one at OHSU. The NIH at the time “thought primate experiments were the future,” Winders told me, and it has shaped the way lots of medical science is practiced to this day. 

But today, the sight of caged lab monkeys looks more like a relic of the past.

It now appears beyond doubt that at least some of what primates are used for in US labs is of extremely limited value, particularly research that aims to model complex mental health conditions in humans, like depression, by inducing them in monkeys. Former NIH director Francis Collins acknowledged as much in 2014, when he referenced “the pointlessness of much of the research being conducted on non-human primates” in a private email that was obtained by PETA as part of a lawsuit. 

And the primates’ very captivity might make results even less translatable to humans. Lahvis, for example, has argued that extreme confinement in cages stunts the health of lab animals and skews the psychology of monkeys to such a degree that they can hardly be seen as sound proxies for healthy humans. 

While proponents of primate research cite its use in human drug development, like therapies for HIV, the mere presence of primate data in the evidence chain for a medical treatment does not prove that that research was indispensable. And given the high moral stakes of research on social, cognitively complex animals, and the substantial opportunity costs of devoting resources and careers to primate labs, merely being sometimes useful does not seem like sufficient justification for subjecting monkeys to lifelong captivity and invasive experiments.

The NIH deserves credit for acting on this perspective. And there is precedent for phasing out research on a class of animals. The federal government a decade ago ended biomedical research on chimpanzees, although other primates are more deeply embedded in such research than chimps were. So, the NIH now faces the challenge of winding down that research enterprise in a way that respects researchers’ careers; building a credible off-ramp to animal-free research tools; and, in its proposal to fund a primate sanctuary, providing some measure of justice for the animals harmed in federally funded science. 

That would be no small task for even a normal administration — and for one that has wrecked its credibility with the scientific community, it will be even harder. Consider it a test case for whether the Trump administration can, amid its ruthless cuts to research, contribute to at least one positive paradigm shift in science.