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UPDATE: Proposed Ban On Use Of Research Chimpanzees Threatens Further Hepatitis B Research, Cure

By Mike Nace
BioMed Texas
June 17, 2013

A new proposal from the U.S. Fish and Wildlife Service (FWS) would give captive chimpanzees used for research the same “endangered” status as their counterparts in the wild, potentially preventing their use for critical research  aimed at developing more effective treatments for Hepatitis B, as well as treatments and vaccines for other serious diseases that plague mankind.

In the wake of a highly controversial set of new proposals from the FWS that may render captive chimpanzees inaccessible to the research community by designating them “endangered,” a top researcher whose institution played a key role in the development of the Hepatitis B vaccine claims that denying investigators access to chimpanzees would have a disastrous effect on critical research needed to treat and cure the disease. Dr. John VandeBerg, Chief Scientific Officer of the Texas Biomedical Research Institute in San Antonio, expressed immediate concern over the proposed change in status for captive chimpanzees, stating that “researchers all over United States are deeply concerned over this announcement,” and going on to say, “I am deeply disappointed. Human and chimpanzee lives will be lost if the proposed rule is implemented.”

BioNews Texas reached out directly to Dr. VandeBerg to follow up on his serious concerns over the FWS proposal. VandeBerg explained that without the use of research chimpanzees, the Hepatitis B vaccine could not have been  developed, due to the facts that only humans and chimpanzees can be infected with Hepatitis B virus, and that the research required to develop an understanding of how to make an effective Hepatitis B vaccine could not have been conducted with human subjects.  Similarly, the use of  chimpanzees in research are required today in order to develop an understanding of how to make drugs that are effective in treating people who have become lifelong “chronic” carriers of Hepatitis B virus (HBV): “The chimpanzee is the only appropriate animal model for developing novel strategies for eradicating HBV from infected people.”

Dr. VandeBerg brought to light a recent editorial in the June edition of Gastroenterology, entitled “Targeting Innate Immunity: A New Step in the Development of Combination Therapy for Chronic Hepatitis B,” wherein esteemed Hepatitis B researcher Fabiene Zoulim lauds Dr. Robert E. Lanford and his colleagues for their recent landmark experiment published in the same journal; the article, entitled  ”GS-9620, an Oral Agonist of Toll-Like Receptor-7, Induces Prolonged Suppression of Hepatitis B Virus in Chronically Infected Chimpanzees,”  states: “Here, we demonstrate that a TLR-7 agonist provides therapeutic efficacy for treatment of HBV (Hepatitis B) chronic infection in chimpanzees, the only primate model of persistent HBV infection.”  The researchers concluded, “The small molecule GS-9620 activates Toll-like receptor 7 signaling in immune cells of chimpanzees to induce clearance of HBV-infected cells. This reagent [which already has moved into clinical trials with human subjects] might be developed for treatment of patients with chronic HBV infection.”

According to the World Health Organization, hepatitis — and Hepatitis B in particular — is one of the most deadly diseases in the world today. The viral, liver-attacking disease has infected two billion people worldwide;  240 million of those people have not been able to clear the virus from their livers and remain chronically infected, and over 600,000 people die of the disease every year. To put the disease in better perspective, the hepatitis B virus is 50 to 100 times more infectious than HIV, and is a particular threat to health workers.

In the U.S., the CDC estimates that there are 1.2 million Americans who are chronically infected with HBV, 38,000 new infections in the U.S. each year, and 3,000 deaths per year.

Although there is currently a Hepatitis B vaccine, thanks to research using chimpanzees, there is still no effective cure for the disease if a person’s immune system fails to clear the virus; much more needs to be done to develop treatments for it. VandeBerg explains that, currently, “the conventional treatment for hepatitis B causes severe side effects and it results after a year of therapy in apparent cure of less than 20% of the patients who can tolerate it,” further spurring on the need to continue developing new, novel treatments for the disease that can be developed and discovered most expeditiously through the continued use of chimpanzees in research.Dr. VandeBerg claims that the new FWS proposal, if implemented, would only allow the use of research chimpanzees through a complex permitting process, which has not been defined by the FWS; impediments to obtaining permits could ostensibly render the use of chimpanzees for developing treaments and cures for  hepatitis, cancer, and auto-immune diseases virtually impossible. FWS has implemented similar permitting processes in the past for other captive populations of endangered primate species used for research, such as the sooty mangabey previously used by Dr. Stewart Zola at the Yerkes Research Center at Emory University.The permitting process, practically speaking, neutralized the use of mangabeys in critical research on AIDS.

Dr. VandeBerg went on to explain that, should the FWS proposal be adopted, a similar permitting processto that is used with mangabeys may be implemented for chimpanzees.

Do Captive Chimps Warrant Being Considered “Endangered” Along With Their Wild Counterparts?

The new FWS proposal by Director Dan Ashe, who was nominated by President Barack Obama and appointed unanimously by the U.S. Congress in 2011, attempts to reverse a decision made in 1990 by the agency to split the classification of wild and captive chimpanzees. Currently, this split listing is the only one of its kind maintained by the agency, which established it in order to allow the NIH to fund medical experiments using captive chimpanzees. The agency, however, claims that, “the rule proposed today would correct this inconsistency,” with Ashe adding that “The most important thing about this is it brings attention to the plight of chimpanzees in the wild.”

Is it fair to conflate the “endangered” status of captive and wild chimpanzees? Dr. VandeBerg, who oversees one of the largest colonies of captive chimpanzees available for biomedical research in the world today, claims that “the captive population of chimpanzees used for research has nothing to do with the wild population” in terms of sustainability and survivability in the world today. In fact, he claims that captive chimps used for research are among the healthiest and most thriving populations of chimpanzees in the world today, far surpassing their counterparts in the wild in terms of health and longevity.  Moreover, the breeding of captive chimpanzees to perpetuate the research population has contributed enormously to ensuring the survival of the species as the wild population is decimated.  VandeBerg says, “The FWS proposal is devastating to the prospects for survival of the species, since there are fewer than 300 chimpanzees in U.S. zoos, and the male chimpanzees at sanctuaries have been vasectomized.  Declaring captive chimpanzees to be endangered will do nothing to stop the demise of the wild population of chimpanzees due to disease, poaching, and habitat destruction.”

Wild chimpanzees are legitimately endangered. Diseases such as AIDS, hunting for the bush meat trade, and continued deforestation and cultural/environmental effects, are decimating their populations in Africa, while the 800+ chimpanzees housed at U.S. research facilities, according to Dr. VandeBerg, are among the best cared-for in the world.The Texas Biomedical Research Institute houses its research chimpanzees in social groups, provides them with extensive enrichment activities, and provides the highest possible level of nutrition as well as  medical and dental care. The institute has five full-time clinical veterinarians, a state-of-the-art pathology lab staff by two Board-certified veterinary pathologists, and a veteran team of caretakers and enrichment specialists, with whom the chimpanzees are closely bonded, all contributing  to  24/7 care and support which keeps their chimpanzees happy and healthy, and engaged in activities and behaviors that are typical for the species.

VandeBerg explains that, researchers and caretakers alike have a moral and ethical responsibility to keep research chimpanzees healthy and well adjusted psychologically, and to treat them with utmost reverence and respect.  He also points out that, in order to be valid research subjects, animals of any species must be in excellent health and not under stress of any kind. The chimpanzee research community is also highly motivated to help the wild chimpanzee population survive and thrive, and it has used captive chimpanzees to test an Ebola hemorrhagic fever vaccine intended to protect wild chimpanzees and gorillas from this lethal disease which is ravaging some wild populations.

The new FWS proposal will remain open for discussion over the next sixty days. During that time, both researchers and animal rights activists alike are likely to lobby intensely on their ideological sides as the FWS finalizes a new set of guidelines that will undoubtedly have a tremendous impact on the use of chimpanzees in scientific research. Perhaps lost in the middle of the debate are the 1.2 million Americans infected with HBV, as well as the two billion infected people worldwide, whose lives may hang in the balance of this landmark decision  which negatively impacts the use of the 800+ chimpanzees that are available for research aimed at advancing science and medicine in America today.