The use of non-human primates in biomedical research is only 0.1 per cent of the total number of animals used for scientific purposes in the EU...
Dr Jan A M Langermans, of the Biomedical Primate Research Centre, states the case for the continued use of non-human primates in biomedical research...
Dr Jan A M Langermans
The use of animals in biomedical research is a sensitive topic and raises concern from the general public. Although no-one is in favour of using animals for research purposes, for both scientific and legal reasons this is, in many cases, still unavoidable. Animals are used for scientific research and to assess safety of new pharmaceuticals, vaccines and other medical products, and in a limited number of cases for specific training purposes of veterinary and human doctors. In general, animal models are essential to fill the gap between in vitro research in the laboratory and ultimate testing in humans. However, it should be noted that non-human primates are only used in cases where the scientific information cannot be obtained in other animal species, so research in primates provides the most suitable option.
The use of non-human primates in biomedical research is only 0.1 per cent of the total number of animals used for scientific purposes in the EU. Their use in biomedical research is restricted to specific basic research and research in relation to potentially life-threatening and debilitating diseases. These include procedures required by legislation for safety and efficacy testing of pharmaceutical products and devices; in fundamentally oriented studies aimed at answering biological questions; and for applied research on development of human medicines.
'Phylogenetic relationship with humans'
The most obvious reason to use non-human primates in biomedical and preclinical research is their close phylogenetic relationship with humans and their shared susceptibility to many human diseases. These animals are instrumental for the promotion of human health and play a critical role in the advancement of various areas in the medical field. At the same time, this close relationship with humans also induces great concern from the general public with respect to their use for research purposes. The EU recognises that, given the current scientific knowledge, the use of non-human primates is still required, but it also specifically states that these animals can only be used when strict conditions have been met. The EU recently adopted a new directive for the protection of animals used for scientific purposes. Directive 2010/63 specifically states that, given the highly developed social and cognitive capacities of non-human primates, specific attention needs to be provided with respect to their housing and care, and specific measures to meet their natural behavioural, environmental, and social needs must be in place.
The use of wild-caught primates for research purposes is prohibited, and animals need to be provided by specialised breeding centres. For this reason, the breeding and use of non-human primates for biomedical research should only be done in dedicated and highly specialised centres and facilities.
The majority of research subjects in Europe are rhesus and cynomolgus macaques (Old World monkeys) and common marmosets (New World monkeys). In a restricted number of research areas, baboons, vervet monkeys and squirrel monkeys are also used for research purposes in Europe. Apes – including chimpanzees – are no longer used in Europe for biomedical research purposes, and the USA is also phasing out their use.
There are currently not sufficient self-sustaining colonies in Europe, and many non-human primates are bred in and imported from non-European countries such as China, Vietnam and Mauritius. Apart from the stress induced by the long-distance transport of the animals, this can also affect the scientific research due to diversity in strain origin and genetics, and in sanitary make-up. Centralised facilities comparable to the national primate research centres in the USA would be of great benefit in this respect. These centres are supported by the National Institute for Health (NIH), have large characterised breeding groups and offer researchers the necessary expertise to study diseases and new treatment models in nonhuman primate models that closely resemble the human situation. Currently, the limited number of primate centres in Europe cannot fulfil the required number of animals and studies.
Studies in non-human primates contribute to our understanding of diseases and fundamental biological phenomena, and they have been – and continue to be – important in the development of new therapies, drugs and vaccines. They also contribute to our general knowledge of processes underlying normal situations and diseases.
In Europe, a number of non-human primates are used in studies required by regulatory authorities. Although safety testing of new pharmaceuticals is mostly done in other animal species, such as rats, dogs and pigs, a limited number of new medicines and therapies require testing in non-human primates. Recent research on new medical treatment demonstrates that specific targets and molecules in the human patient become more important, and that in a number of cases these targets can only be found in non-human primates.
HIV and AIDS
Because non-human primates are naturally susceptible to many infectious diseases that also affect humans, they can provide interesting animal models for studying new therapies and vaccines. Rhesus macaques provide an important animal model for the study of disease and development of therapeutics and vaccines against HIV and AIDS. In contrast to other animal species, macaques can be infected with the natural primate counterpart of HIV (simian immunodeficiency virus, or SIV), resulting in the development of a disease similar to that described in AIDS patients. These models have been very important for the development of new strategies to protect HIV-infected people from developing AIDS. Many of the current therapies would not have been possible without the research that has been performed in macaques.
Macaques are also used in research on other viral diseases. A recent example is that of influenza, where macaques are used as an experimental model for studying pathogenesis and immunology of the virus. Influenza-infected macaques develop immune responses and disease symptoms comparable to those of humans, and viral replication can be detected in nasal areas and respiratory tract. Macaques are used to test new vaccines against various influenza strains from human and avian origin.
Non-human primates also play an important role in studies on emerging infectious diseases and vaccine development, such as West Nile virus, Rift Valley fever virus and SARS, as well as tuberculosis and malaria. The non-human primate model is used for fundamental research aimed at understanding disease processes in these infectious conditions and is instrumental in identifying correlates of protection as well as new vaccines and medicines. The model contributes to rational selection of new treatments and vaccines to progress to advanced clinical studies, which are costly and time-consuming.
Other important areas where non-human primates play an important role are brain research and immune related disorders. The way in which the brains of non-human primates are organised is highly similar to that of humans, and non-human primates can be essential in answering scientific questions with respect to brain function and development, and in studying complex conditions such as Parkinson’s disease, Alzheimer’s and multiple sclerosis.
Non-human primates contribute to our understanding of diseases and fundamental biological phenomena, and they have been and are important in the development of new therapies, drugs and vaccines. In this way, non-human primates are instrumental for the promotion of human health and play a critical role in the advancement of various areas in the medical field. However, the decision to use non-human primates should always be accompanied by optimal care and housing of these highly developed animals. The new EU Directive 2010/63 provides the necessary guidance needed for welfare and husbandry of non-human primates. Compared to many other areas in the world, Europe has very high welfare requirements, such as very large cages and social housing of experimental animals, and involvement of well-designed enrichment and training programmes for the animals. Europe is in a unique position to warrant that the use of non-human primates for biomedical research goes hand-in-hand with optimal care for the animals. Since it is clear that non-human primates are still essential in biomedical research, banning non-human primate research from Europe would result in outsourcing of primate research to countries where welfare standards might be lower.
Dr Jan A M Langermans
Animal Science Department
Biomedical Primate Research Centre
[This article was originally published on 9th
April 2013 as part of Science Omega Review Europe