The Shortage of Non-Human Primates Available for Research Opens a Door for Non-Animal Test Methods
By Sherman McFarland | September 14, 2023
Federal agencies and elected officials should not view the shortage of non-human primates (NHP) available for research as a problem that needs to be fixed by acquiring more NHPs. The real problem is what the NHP shortage allegedly does: impedes research. Therefore, the Biden Administration, Congress, NIH, FDA, and other relevant agencies should view the NHP shortage as an opportunity to enable research by heavily encouraging the use and development of, and dramatically increasing funding for, human-relevant, non-animal test methods.
The National Academies of Sciences (NAS) released a study report in early May titled “Nonhuman Primate Models in Biomedical Research: State of the Science and Future Needs.” In that report, the NAS advocated for further use of non-human primates (NHPs):
“Although nonhuman primates (NHPs) represent a small proportion—an estimated one-half of 1 percent—of the animals used in biomedical research, they remain important animal models due to their similarities to humans with respect to genetic makeup, anatomy, physiology, and behavior. Remarkable biomedical breakthroughs, including successful treatments for Parkinson’s and sickle cell disease, drugs to prevent transplant rejection, and vaccines for numerous public health threats, have been enabled by research using NHP models. However, a worsening shortage of NHPs, exacerbated by the COVID-19 pandemic and recent restrictions on their exportation and transportation, has had negative impacts on biomedical research necessary for both public health and national security.”
Despite its support for the use of NHPs, one of the conclusions reached by the NAS in its study report was that even though there are no alternatives that can fully replace NHPs, there is reason to be optimistic because new approach methodologies, such as in vitro and in silico models, continue to advance. In addition, the NAS concluded that “[c]ontinued development and validation of new approach methodologies (in vitro and in silico model systems) is critically important to support further advances in biomedical research. This may reduce the need for nonhuman primate (NHP) models in the future, and/or enhance their utility. Additionally, this may help to mitigate shortages in NHP supply and the high cost of NHP research.”
The United States uses about 70,000 NHPs per year for brain, infectious diseases, and aging studies. China stopped exporting NHPs in 2020, which contributed to the NHP shortage in the United States because the United States, at that time, imported 60% of its NHPs from China. In particular, the United States experienced a 20% drop in imports of cynomolgus macaques, the proper name of which is crab-eating or long-tailed macaques, which is a species used by private industry for drug and vaccine research.
In addition, the shortage of NHPs was worsened last year. Eight people were indicted by the Department of Justice for smuggling long-tailed macaques into the United States, and for conspiracy to violate the Lacey Act and Endangered Species Act in November 2022. Two of the eight people indicted for smuggling and conspiracy were Cambodian officials of the Cambodian Forestry Administration. Long-tailed macaques are an endangered species. The indicted persons allegedly removed wild, long-tailed macaques from national parks and other protected areas in Cambodia, then took the macaques to breeding facilities where the macaques were provided fraudulent export permits, which falsely stated that the macaques were bred in captivity. As a result, Cambodia stopped exporting NHPs, which is expected to significantly impair drug development in the United States. In fact, as of September 30, 2022, Cambodia accounted for 60% of American imports of NHPs. Furthermore, Inotiv, the largest commercial dealer of NHPs in the United States, decided to halt sales of all Cambodian NHPs in its possession in the United States.
An additional factor contributing to the NHP shortage is that dozens of airlines across the world have refused to transport NHPs to laboratories for use in research. Considering this factor along with the reality that Chinese and Cambodian NHPs are unavailable to the United States, it is important that the federal government treat the NHP shortage as an opportunity to advocate and dramatically increase funding for non-animal test methods. Funding directed toward the development and validation of non-animal test methods will enable the ability to more rapidly replace NHPs in research and drug development. As non-animal test methods such as organs-on-a-chip and organoids are developed, refined, mass-produced, and become affordable for American laboratories to use, American research can progress without being hampered by a lack of NHPs, or a reliance on the countries that supply them. Furthermore, available information indicates that non-animal test methods are cheaper, can be performed faster, are just as reliable (if not more so), and do not subject animals to suffering or death, when compared to traditional animal test methods. Moreover, the shortage of NHPs should induce the federal government to fund and promote the use of non-animal test methods that are available to laboratories, including stem cells, in silico models, and microdosing.
In conclusion, the NHP shortage is not a problem by itself. The problem is that the NHP shortage impedes biomedical research, and it cannot be solved by merely acquiring more NHPs. The need to enable biomedical research to discover treatments of diseases and public health threats means that it is critical for the NIH, FDA, Congress, and Biden Administration to immediately fund and encourage the use and development of human-relevant, non-animal test methods, rather than continue to struggle acquiring NHPs.
The views expressed do not necessarily reflect the official policy or position of Johns Hopkins University or Johns Hopkins Bloomberg School of Public Health.
