1. National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
2. Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
3. New York State Department of Health, Albany, New York, USA
4. Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
5. Connecticut Department of Public Health, Hartford, Connecticut, USA
6. Vanderbilt University School of Medicine, Nashville, Tennessee, USA
7. New Mexico Department of Health, Santa Fe, New Mexico, USA
8. Oregon Health Authority, Portland, Oregon, USA
9. Minnesota Department of Health, St Paul, Minnesota, USA
10. California Department of Public Health, Richmond, California, USA