1. Department of Research, HealthPartners Institute, Minneapolis, Minnesota
2. The Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon
3. The Vaccine Study Center, Kaiser Permanente Northern California, Oakland, California
4. Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, California
5. Institute for Health Research, Kaiser Permanente Colorado, Denver, Colorado
6. Marshfield Clinic Research Institute, Marshfield, Wisconsin
7. Kaiser Permanente Washington, Health Research Institute, Seattle, Washington
8. Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut
9. Centers for Disease Control and Prevention, Atlanta, Georgia
10. Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Division of Epidemiology, US Food and Drug Administration, Silver Spring, Maryland