1. HealthPartners Institute, Minneapolis, Minnesota
2. Institute for Health Research, Kaiser Permanente Colorado, Denver, Colorado
3. Kaiser Permanente Vaccine Study Center, Oakland, California
4. Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon
5. Ambulatory Care Services, Denver Health, Denver, Colorado
6. Kaiser Permanente Washington, Seattle
7. Marshfield Clinic Research Institute, Marshfield, Wisconsin
8. Kaiser Permanente Southern California, Pasadena
9. Immunization Services Division, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia
10. Immunization Safety Office, US Centers for Disease Control and Prevention, Atlanta, Georgia