We propose to establish a Johns Hopkins (JHU) Clinical Trial Unit (CTU) with three affiliated Clinical Research sites (CRS): two in Kampala, Uganda, and one in Manning, China. The proposed CTU structure includes joining of two CTU leaderships and clinical research sites with outstanding performance over the past grant cycle. The successful performance includes high enrollment of over 3700 participants and retention rates between 83% and 97%; a consistent track record as the leader of network scientific contributions; and successful conduct of high priority HIV Prevention and Therapeutic clinical trials within three of the current NIH HIV Clinical Trial Networks. The Johns Hopkins Kampala -Nanning (K-N) CTU proposal will be led by two PD/PIs, Professors Mary Glenn Fowler and Brooks Jackson, who have worked collaboratively in various roles over the past 22 years to conduct clinical trials on HIV prevention and HIV therapeutics and its complications. This CTU will have its central administrative base at JHU in Baltimore, MD and will conduct the network HIV clinical protocols at two CRSs in Kampala, Uganda and one CRS in Nanning, China. 1. The Makerere U. Johns Hopkins U. Research Collaboration (MU-JHU) CRS will be affiliated with a) the Clinical Research Network for HIV/AIDS and HIV associated Infections in Pediatric and Maternal Populations focusing on PMTCT and treatment of HIV infected infants and young children; b) the Network on Integrated Strategies to Prevent HIV Infection; and c) the Network on Microbicides to Prevent HIV Infection. 2. The Pediatric Infectious Diseases Clinic/ Baylor College of Medicine Children's Foundation of Uganda Institute (PIDC) CRS, an independent nonprofit NGO entity in Uganda will focus on pediatric and adolescent HIV treatment trials and will be affiliated with the Network on Infections in Pediatric and Maternal Populations. 3. The Nanning CRS site in Nanning China will be affiliated with a) the Network for HIV/AIDS and HIV associated Infections in Pediatric and Maternal Populations focusing on PMTCT and treatment of HIV infected infants and young children; b) the Network on Integrated Strategies to Prevent HIV Infection; and c) the Network on Therapeutics for HIV and associated infections. RELEVANCE: The configuration of the JHU K-N CTU/CRS is designed to maximize the capacity for high enrollment of diverse at-risk international populations (adult injection drug users, women at risk, pregnant women and children) and to carry out the state-of-the-art HIV research agenda proposed within four clinical trial networks to significantly reduce HIV related morbidity and mortality in these populations.