At the beginning of April the European Commission’s Scientific Steering Committee adopted a four page statement outlining, “The Need for Non-Human Primates in Biomedical Research,” that aptly made the case for the ongoing importance of medical research involving non-human primates.
The Steering Committee’s statement reads, in part,
Whether or not, eventually, non-human primates are used for research, will need to be decided upon a case-by-case basis, and following a careful assessment, which takes into account the justification below, the possible existence of alternatives, ethical considerations and the problems that could result from not using the non-human primates. The SSC stresses that unnecessary and duplicated or redundant research using non-human primates should be avoided at all costs . . . However, it considers that for certain experiments there are no alternatives to the use of non-human primates.
The rest of the four-page report is an excellent summary of the irreplaceable nature of primate research. For example, on primate research into malaria, the Steering Committee notes that animal alternatives simply cannot accomplish everything that needs to be done in investigating malaria,
Although considerable research can be done in vitro, the [malaria] parasite has obligatory intra-hepatic developmental phases that are not amenable to in vitro cultivation. To date primates have been used as pre-clinical screens for a variety of new vaccine candidates, based on recombinant sub-unit approaches and live-vectored approaches. Different malaria vaccines will require different immune responses (humoral or cellular) and well-characterized models with similar immune responses to humans (such as macaques) are essential in vaccine development. New malaria drugs will have to work effectively in vivo, and many drugs that are effective in vitro fail in vivo. Monkey models are vital to evaluate promising new drugs for efficacy.
When the Steering Committee says that the malaria parasite “has obligatory intra-hepatic developmental phases,” what it means is that when people are infected with malaria the parasites travel through the blood stream through the liver where they enter the liver’s cells and begin to multiply. Then after a period of time lasting as little 8 days to as long as several months, the malaria parasites leave the liver and enter red blood cells.
When researchers study malaria, they need to study this phase during which the malaria parasite “incubates” in the liver. It is simply not possible at the moment to study that sort of complex behavior in vivo — researchers need to infect non-human primates with malaria parasites to study it. There simply is no animal alternative.
Similarly, with tuberculosis primate studies are vital for narrowing the number of potential treatments that go into clinical trials (which are, after all, extremely expensive). The Steering Committee writes,
Mouse and guinea pig models are used to screen potential new vaccines and drugs, however their patterns of disease and their immune responses are often markedly different from those seen in humans. Recently a careful analysis of two macaque models (rhesus and cynomolgus) has shown the value of these two models and their similarity to the human situation. These models are now being used to screen and select among new candidate vaccines before embarking on the complex, protracted and expensive clinical phase.
And then there are diseases where primates are literally the only experimental model available. Such is the case with Hepatitis C,
Hepatitis C cannot be cultured and the only other species other than man that can be infected is the chimpanzee. Early HCV vaccine studies in chimpanzees have begun to show progress but non-human primate research is essential to bring a truly effective vaccine to the clinic. Thanks to studies in chimpanzees which are still alive and healthy today, millions of doses of a very successful Hepatitis B vaccine have been given World-wide. However, Hepatitis B is still transmitted and many new infections occur daily. New less expensive HBV vaccines are required for developing countries to halt and eliminate this chronic human pathogen.
And yet most European countries seem convinced that primate research can be outlawed altogether with no impact on the biomedical progress. In fact there is but a single research facility in all of Europe that conducts research involving chimpanzees and animal rights activists are pushing for a European Union-wide ban on all research involving great apes.
Source:
The Need for Non-Human Primates in Biomedical Research. Statement of the Scientific Steering Committee of the European Commission, Adopted at its Meeting of 4-5 April 2002.