1. Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, USA
2. Department of Microbiology, Boston University, Boston, Massachusetts, USA
3. Vaccine Research Center, NIH, Bethesda, Maryland, USA
4. Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
5. California National Primate Research Center, University of California, Davis, California, USA