1. Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
2. Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA.
3. Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.
4. Laboratory of Molecular Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA.
5. Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
6. Departments of Immunology and Surgery, Duke University School of Medicine, Durham, NC 27710, USA.
7. Departments of Pediatrics and Immunology, Duke University School of Medicine, Durham, NC 27710, USA.
8. Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
9. Bioqual, Inc., Rockville, MD 20850, USA.
10. Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA.
11. Department of Mathematics and Statistics, Boston University, Boston, MA 02215, USA.
12. Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.