1. HealthPartners Institute Minneapolis Minnesota USA
2. Children's Minnesota Research Institute Minneapolis Minnesota USA
3. Institute for Health Research Kaiser Permanente Colorado Denver Colorado USA
4. Center for Health Research Kaiser Permanente Northwest Portland Oregon USA
5. Kaiser Permanente Vaccine Study Center Oakland California USA
6. Kaiser Permanente Southern California Los Angeles California USA
7. Kaiser Permanente Washington Seattle Washington USA
8. Ambulatory Care Services Denver Health Denver Colorado USA
9. Marshfield Clinic Research Institute Marshfield Wisconsin USA
10. Harvard Pilgrim Healthcare Institute Boston Massachusetts USA
11. Centers for Disease Control and Prevention Atlanta Georgia USA
12. University of Iowa Iowa City Iowa USA