First Conservation Vaccine Trial on Chimpanzees
Captive chimpanzees have for the first time been used to test a vaccine to protect wild chimpanzees rather than humans. Published in Proceedings of the National Academy of Science, a new paper shows that a vaccine against the deadly Ebola virus caused no serious side effects and evoked a robust immune response.
Infectious diseases like Ebola have recently emerged as a major threat to wild chimpanzees and gorillas but a viscerally non-interventionist ape conservation community has opposed invasive responses that upset a perceived “natural balance”. “This is not the Garden of Eden”, said Apes Incorporated (ApesInc.org) President and University of Cambridge Lecturer Peter Walsh, senior author on the paper. “It is the Wild West, awash in commercial bushmeat hunting, mechanized logging, and human disease. ‘Extreme Conservation’ measures such as vaccination hold the only hope for preventing ape extinction”.
The trial illustrates the conservation potential held by “orphan” vaccines which show excellent safety and immunity profiles in captive primate trials but have not yet gained the extensive funding needed for human licensing. Chimpanzees were vaccinated with a “virus like particle” vaccine developed by Maryland biotech firm Integrated Biotherapeutics (IBT). “VLP vaccines are particularly promising for use in endangered species because they cannot cause infection and spread between animals”, said IBT Vice President Kelly Warfield. The trial was supported by the Paul G. Allen Family Foundation and included contributions from researchers at the US Army Medical Research for Infectious Disease, the National Institutes of Health, and the University of Louisiana at Lafayette’s New Iberia Research Center, where the trial was conducted.
This promise of vaccination may never be realized because pending regulations to classify captive chimpanzees under the US Endangered Species Act would outlaw further biomedical research on chimpanzees. The closure of facilities doing human-focused biomedical research on chimpanzees is a conservation catastrophe, according to Walsh, because it will leave no place to do the rigorous safety testing that park managers insist on before vaccines are given to immunologically vulnerable wild apes. The US is the only developed country where such testing is still allowed.
The move by the US Fish and Wildlife Service to list captive chimpanzees under the Endangered Species act is only the latest in a series of US Government actions spurred by animal rights activists seeking to end biomedical testing on chimpanzees. There has also been a National Academies of Science blue ribbon panel and an internal policy review by the National Institutes of Health. Although the National Academy panel was specifically mandated by Congress to consider the conservation implications of ending biomedical testing on chimpanzees, neither the Academy’s report, the NIH policy review, nor the regulations proposed by USFWS addressed this important topic.
Vaccination is an important ape conservation issue because over recent decades Ebola virus has killed about one third of the world gorilla population and large numbers of chimpanzees, contributing to the World Conservation Union’s (IUCN) decision to list common chimpanzees as Endangered and western gorillas as Critically Endangered. Human respiratory virus spillover also accounts for about half of deaths among wild chimpanzees and gorillas habituated to close human approach for tourism and research. Most of these viral diseases are preventable: either with vaccines already licensed for human use or with orphan vaccines.
Walsh and coauthors argue that because many of the researchers and tourists that infect wild apes are Americans and because countless wild chimpanzees were killed to originally stock US biomedical labs, the US Government and, particularly, NIH should shoulder the responsibility for alleviating the threat to the wild apes. They call for NIH to establish and support a captive chimpanzee population dedicated solely to conservation research. This population would be used to both safety test conservation vaccines and develop associated technologies such as baiting systems for delivering vaccines orally and non-invasive assays for confirming the immune response to vaccination, measuring whether the psychological stress caused by tourism and research suppress gorilla and chimpanzee immune function, and screening tourists for dangerous respiratory viruses.
Apes Incorporated has an active research program on these and other applications but finds it difficult to raise funds because of the controversial nature of such research: government funding bodies are particularly averse to negative publicity. “The willingness of the Paul G. Allen Family Foundation to fund this work despite the controversy is a perfect example of the critical role that private foundations have to play in preventing ape extinction”, said Walsh. “They understand that not all critical conservation actions will be by consensus. We need to break some eggs to make the conservation omelet. To paraphrase the AIDS prevention movement, Porridge = Death”.