1. Emory Vaccine Center, Emory University, Atlanta, Georgia, USA
2. Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA
3. Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, USA
4. Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
5. Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, USA