1. Institute of Molecular Virology, University Clinic of Ulm, 89081 Ulm, Germany
2. Tulane National Primate Research Center, Tulane University, Covington, Louisiana 70433
3. Center for Vaccine Research and Departments of Pathology and Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261-9045
4. Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
5. Unit of Infection Models, German Primate Centre, 37077 Göttingen, Germany