1. University of Washington, Department of Medicine, Seattle, Washington, USA
2. Department of Global Health, Seattle, Washington, USA
3. Department of Epidemiology, Seattle, Washington, USA
4. Fred Hutchinson Cancer Research Center, Vaccine and Infectious Disease Division, Seattle, Washington, USA
5. Department of Biostatistics, Seattle, Washington, USA
6. University of Nairobi, Institute of Tropical and Infectious Diseases, Nairobi, Kenya
7. Kenya AIDS Vaccine Initiative (KAVI)-Institute of Clinical Research, Nairobi, Kenya
8. University of Alabama at Birmingham, Division of Infectious Diseases, Birmingham, Alabama, USA