on human health have come from infectious-disease research that focused on the development of vaccines and new classes of therapeutic agents. Instances in which the use of chimpanzees was considered either critical or a prerequisite to introducing an agent into humans include development and safety testing of vaccines for hepatitis B virus (HBV) and identification of the hepatitis C virus (HCV) both of which had enormous benefit to humankind; and development of novel inhibitors of neutrophil elastase. Those and other examples warrant additional discussion to emphasize the value of chimpanzees as an experimental model of human health problems.
Experimental infection of chimpanzees as animal models in biomedical research has involved such diverse microorganisms as mycoplasma species, the filarial nematode Onchocerca volvulus, numerous viruses, and unconventional agents associated with subacute degenerative diseases of the central nervous system (such as spongiform encephalopathies, including kuru and Creutzfeldt-Jakob disease). Major contributions to human health have resulted from the use of chimpanzees in studies to control transmission of and disease induced by the hepatitis viruses, respiratory syncytial virus, and human immunodeficiency virus (HIV).
Early research on HBV was hindered by the inability to propagate it in tissue culture. Because chimpanzees are the only nonhuman primates susceptible to infection with HBV, they were critical to the development of a vaccine by providing a source of virus and viral antigens and by making it possible to evaluate the safety and the effectiveness of candidate vaccines. The benefits of HBV vaccination to humanity can be characterized as not only controlling an important disease but also presenting a potential approach to controlling the transmission of disease from mother to child, thereby eliminating a major problem for mankind, particularly in Asia, but also in the United States. Even though hepatitis B is relatively rare in the United States, the major vaccine-recommending bodies, including the American Academy of Pediatrics and the Immunization Practices Advisory Committee, now recommend universal hepatitis B vaccination of newborns. This is important because about 75% of