1. HIV Center for Clinical and Behavioral Studies at New York State Psychiatric Institute and Columbia University, New York, New York.
2. University of Zimbabwe College of Health Sciences Clinical Trials Research Center, Harare, Zimbabwe.
3. Makerere University–Johns Hopkins University Research Collaboration Clinical Research Site, Kampala, Uganda.
4. Queen Elizabeth Central Hospital, College of Medicine Clinical Research Site, Blantyre, Malawi.
5. South African Medical Research Council Clinical Trials Unit, Durban, South Africa.
6. CAPRISA, Durban, South Africa.