1. Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California.
2. Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, Maryland.
3. Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland.
4. Laboratory of Viral Diseases, National Institutes of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland.
5. Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland.