1. Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
2. Department of Global Health, University of Washington, Seattle, Washington.
3. Department of Epidemiology, University of Washington, Seattle, Washington.
4. Infectious Disease Institute, Makerere University, Kampala, Uganda.
5. Department of Medicine, University of Washington, Seattle, Washington.
6. Department of Pediatrics, University of Washington, Seattle, Washington.