1. Center for Biomedical Research, Population Council, New York, New York 10021.
2. Department of Medical Microbiology and Immunology of Infection, Charité–University Medicine, Berlin, Berlin, Germany.
3. Henry M. Jackson Foundation, Rockville, Maryland 20850.
4. University of Washington, St. Louis, Missouri 63130.
5. Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294.
6. BIOQUAL Inc., Rockville, Maryland 20850.
7. AIDS Vaccine Program, SAIC-Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702.
8. Aaron Diamond AIDS Research Center, Rockefeller University, New York, New York 10016.
9. Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland 20892.