Historical biomedical applications of NHP test systems (and other animal model systems) have been driven by availability of animals and background control data.
Indian-derived rhesus macaques, which were readily accessible at the time of early polio vaccine development were used extensively for this urgent need and adopted for broader biomedical purposes. Rhesus monkeys continue to be a core resource for U.S. national primate centers. However, tightened access to rhesus macaques with geopolitical shifts directed attention to cynomolgus macaques and African green monkeys.
Over time cynomolgus monkeys were more heavily adopted for ease of access to wild Southeast Asian populations and the perceived higher risk of zoonosis in African-derived green monkeys. While this contributed to extensive background control data development for cynomolgus monkeys, particularly for safety endpoints, comparative clinical relevance over other primate species was not a principal driver to selection of cynomolgus monkeys as a test system.
With broadening application of NHPs to therapeutic development, normative datasets have emerged for African green monkeys, establishing the substantial comparability to macaque species across many parameters. Homology analyses of the green monkey reference genome, derived from St. Kitts-origin animals, further confirms the green monkey to be evolutionarily equidistant to humans, with loci of tighter genome and proteome homology than macaques.
