1. Department of Medicine; Duke University Medical Center; Durham North Carolina 27710 U.S.A.
2. Infectious Disease Section; Veterans Affairs Medical Center; Durham North Carolina 27705 U.S.A.
3. Department of Molecular Genetics and Microbiology; Duke University Medical Center; Durham North Carolina 27710 U.S.A.
4. Department of Immunology; Duke University Medical Center; Durham North Carolina 27710 U.S.A.
5. Department of Pathology; Duke University Medical Center; Durham North Carolina 27710 U.S.A.
6. Human Vaccine Institute; Duke University Medical Center; Durham North Carolina 27710 U.S.A.