PROJECT SUMMARY/ABSTRACT: The major goal of this application is to sustain the Specific Pathogen Free (SPF) program at the Caribbean Primate Research Center's (CPRC) through support of operations, administration, veterinary care, virological and MHC typing and by the improvement of our comprehensive genetic management plan. A unique feature of CPRC animals in favoring a successful establishment and sustainable of SPF colony are that these animals are naturally free of SIV and SRV-D, two of the four viruses to be tested for. Nevertheless, for safety and as required for the SPF Program, we continue systematically testing for all four viruses (B virus, STLV, SIV and SRV-D). The Program provides unadmixed Indian-origin rhesus monkeys with defined genetic and virological background. The primary purpose of the virology testing arm of CPRC-SPF breeding program is to assure that its Indian- origin rhesus macaque colony, supporting NIH-sponsored research specially on HIV/AIDS, is free of the above- mentioned viruses. An advantage of this program is that it has been closed to external individuals since 2015. Certainly, this aspect substantially decreases the risks of the re-introduction of any of the four tested viruses from an external source.