1. Boston Children's Hospital Boston MA
2. University of Utah School of Medicine Salt Lake City UT
3. University of Mississippi Medical Center Jackson MS
4. University of California San Francisco Medical Center San Francisco CA
5. Ann & Robert H. Lurie Children's Hospital of Chicago IL
6. Children's Healthcare of Atlanta Emory University School of Medicine Atlanta GA
7. Centers for Disease Control and Prevention Atlanta GA
8. Seattle Children's Hospital Seattle WA