1. Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland;
2. United States Army Medical Research Directorate – Kenya, Nairobi, Kenya;
3. Center for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya;
4. Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland
5. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland;