Non-human primates: essential partners in biomedical research

Non-human primates are complex species, and their use in research requires special and dedicated care, attention and adequate housing conditions. Scientists recognize that these factors are essential to produce accurate research results. The application of non-human primates for biomedical research is in most countries tightly regulated by law, and all research protocols have to be screened for scientific and ethical merits. Moreover, primate centers, academic institutions and their associated researchers collaborate in several well-organized networks, thus avoiding duplication of experiments. As a result, the use of non-human primates in biomedical research is highly restricted. In the Netherlands, for example, non-human primates constitute approximately 0.1% of the total number of animals used for biomedical experiments. One should realize that as the Netherlands harbors one of the few European primate centers, 0.1% is therefore a relatively high figure because primate centers have a so-called hotel function and attract researchers from regions/countries that lack such a specialized facility. Non-human primates are important models to study human disease or biology because they share a high degree of similarity with their human counterparts. For example, apart from humans, only chimpanzees are susceptible to the liverstage infection with Plasmodium falciparum that may cause malaria. Hepatitis viruses are also known to infect humans and some great ape species. In the case of many chronic disorders, as well as some infectious diseases, the actual diagnosis of pathology may take place long after the initial event that provoked the disease. This late observation may hamper the understanding of which cascade of events (infection, stress, etc.) triggered the onset of disease. In this context, experimental animal models may provide valuable insights and information. Since non-human primates respond like their human counterparts to a large range of similar pathogens, they are extremely important in studying the mechanisms of immune pathology directly following infection/immunization. This type of fundamental knowledge, which for ethical reasons can not be obtained from human experiments, will certainly provide the basis for future immune intervention therapies and vaccine strategies.