1. Perinatal HIV Research Unit, Chris Hani Baragwanath Hospital, Soweto, South Africa.
2. Uganda Virus Research Institute—International AIDS Vaccine Initiative (UVRI-IAVI) HIV Vaccine Program, Entebbe, Uganda.
3. MRC-UVRI Uganda Research Unit on AIDS, Entebbe, Uganda.
4. Desmond Tutu HIV Centre, Cape Town, South Africa.
5. Department of Medical Microbiology, Medunsa, Pretoria, South Africa.
6. Zambia Emory HIV Research Program, Lusaka, Zambia.
7. The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 and Columbus Children's Research Institute, Columbus, Ohio.
8. Targeted Genetics Corporation, Seattle, Washington.
9. The EMMES Corporation, Rockville, Maryland.
10. International AIDS Vaccine Initiative, Human Immunology Laboratory, Imperial College, London, UK.
11. International AIDS Vaccine Initiative, New York, New York.
12. IAVI Southern Africa Regional Office, Johannesburg, South Africa.