1. Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
2. Department of Microbiology, Immunology, and Parasitology, Louisiana State University, New Orleans, Louisiana.
3. Duke University Medical Center, Human Vaccine Institute, Durham, North Carolina.
4. California National Primate Center, University of California, Davis, California.
5. Emory University and Yerkes National Primate Research Center, Atlanta, Georgia.