1. U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Rockville, Maryland 20850.
2. Centre for Geographic Medicine Research–Coast, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya.
3. Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Headington, UK.
4. University of Washington, Seattle, Washington 98109.
5. International AIDS Vaccine Initiative, New York, New York 10038.