In a major policy reversal, the Trump administration has instructed the US Centers for Disease Control and Prevention (CDC) to cease all scientific studies involving monkeys and apes. This directive forms a key part of a broader push to reduce and ultimately eliminate animal testing in federally funded research.
Details of the New Directive
An exclusive plan shared with the Daily Mail reveals that the CDC must now halt any new research involving non-human primates (NHPs). For ongoing experiments, the agency is tasked with finding ways to terminate them as swiftly and ethically as possible. A spokesperson for the Department of Health and Human Services (HHS) clarified that the affected work is 'long-term basic research' driven by fundamental scientific inquiry, such as investigating the causes of Alzheimer's disease or refining surgical methods, rather than specific product development.
The CDC must evaluate each of the approximately 500 primates it is believed to care for—a figure dating from 2006, with current numbers unclear—to identify which are healthy enough for relocation to approved sanctuaries. The administration has not detailed plans for animals deemed too ill to be moved. The agency is also required to establish a rigorous vetting process for potential sanctuaries, estimate costs, and ensure high-quality facilities. At least ten such sanctuaries exist across the United States.
Recognising this process will take time, the CDC must employ the best methods to minimise pain, distress, or discomfort for any primates remaining in its temporary care. Furthermore, the CDC will develop a separate strategy to reduce its overall use of animals in research, ensuring any remaining animal studies are directly aligned with its core mission to protect American public health.
Impact and Controversy in Medical Research
Non-human primates, including species like macaques, marmosets, and baboons, represent a small fraction—estimated at just half of one percent—of all animals used in US biomedical research. The vast majority (around 95%) involves mice and rats, which are unaffected by this new policy. However, NHPs are considered vital in areas like neuroscience, HIV/AIDS, immunology, and vaccine development due to their close biological similarity to humans.
Research procedures on primates can be highly invasive. To model diseases such as Parkinson's, they may undergo brain surgery, have chemical lesions induced, or be genetically modified. In toxicology tests, they can be force-fed or injected with substances to determine lethal doses, processes that can cause vomiting, seizures, and fatal organ failure.
Critics, including animal rights groups and some scientists, argue that such suffering is not only cruel but often scientifically wasteful, pointing to high failure rates in translating findings to humans, particularly in AIDS research. Dr. Kathy Strickland, a veterinarian with experience in research labs, told the Daily Mail she witnessed serious welfare and ethical concerns. 'Tens of thousands of these sentient beings are destroyed in the name of science each year,' she stated, advocating for modern alternatives.
The Future of Research and Remaining Questions
This policy shift marks the first time a US agency has ended its in-house non-human primate programme, aside from the National Institutes of Health's (NIH) retirement of research chimpanzees a decade ago. It is important to note that the directive only affects CDC labs and does not apply to the hundreds of NIH-funded institutions that conduct animal research.
The move aligns with other Trump administration initiatives, such as the Food and Drug Administration's (FDA) April announcement to replace NHP testing for certain drugs with more modern methods. An HHS spokesperson confirmed that 'there will be no testing on humans in place of this at CDC.' The future will rely more on alternatives like AI-based computational models and lab-grown human tissues (organoids), though experts acknowledge these cannot yet fully replicate the complex, system-wide physiology of a whole living primate for some studies.
Animal rights organisations like PETA have long campaigned against primate research. The policy change places renewed scrutiny on major facilities, such as the Oregon National Primate Research Center, which houses about 5,000 monkeys for basic science. The ultimate fate of the CDC's primates—sanctuary placement or euthanasia—remains a poignant and unresolved aspect of this significant policy turn.
