1. National Vaccine Program Office, US Department of Health and Human Services, Washington, DC;
2. National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia;
3. Hubert Department of Global Health Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia;
4. Department of Pediatrics, Vanderbilt Vaccine Research Program, Vanderbilt University Medical Center, Nashville, Tennessee;
5. Division of Pediatric Infectious Diseases, Stanford University School of Medicine, Stanford, California; and
6. Kaiser Permanente Vaccine Study Center, Oakland, California