The mission of the Department of Retrovirology is to prepare for and conduct clinical trials (phases I-III) of preventive HIV vaccines for use in U.S. military members deployed to HIV endemic areas outside the United States. This mission is supported through i) the evaluation of candidate vaccines for safety, immunogenicity and efficacy, ii) the identification and characterization of potential cohorts for phase III vaccine trials, iii) the establishment of diagnostic assays which differentiate infection from vaccine-induced immune responses, and iv) the establishment of virologic methods to characterize the HIV viruses circulating in risk areas and potential sites of vaccine trials and immunological methods to characterize the responses induced by candidate vaccines.