1. Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA
2. Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
3. Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
4. Department of Microbiology and Immunology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
5. Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
6. California National Primate Research Center, University of California, Davis, Davis, California, USA