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