1. Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 1864, South Africa.
2. South African Medical Research Council, Cape Town 7505, South Africa.
3. Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
4. The Desmond Tutu HIV Centre, University of Cape Town, Cape Town 8001, South Africa.
5. Cape Town HVTN Immunology Laboratory, Hutchinson Centre Research Institute of South Africa, Cape Town 8001, South Africa.
6. Vaccine Research Program, Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852, USA.
7. The Aurum Institute, Klerksdorp 2570, South Africa.
8. National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa.
9. Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
10. Sanofi Pasteur, Swiftwater, PA 18370, USA.
11. Global Solutions for Infectious Diseases, South San Francisco, CA 94080, USA.
12. US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.