A safe and effective vaccine remains the best hope of controlling the human immunodeficiency virus (HIV) pandemic. Because of the similarity of the immune system of the Indian-origin rhesus macaques and humans, vaccine development is heavily dependent on the SIV and SHIV macaque models. The need for Indian rhesus macaques for AIDS-related research continues to exceed availability. Efficient domestic breeding programs managed to produce well characterized animals that enhance their use in biomedical research and offer the best long term solution for the current shortage of Indian-origin rhesus macaques for AIDS vaccine and pathogenesis studies and to insure future availability. The purposes of this proposal are to continue to support and characterize the specific pathogen-free Indian rhesus AIDS Research Colony resource that was established in the past ten-year grant period.