1. Department of Pediatrics, Division of Infectious Diseases, Ann & Robert H. Lurie Children's Hospital, Northwestern University Feinberg School of Medicine, Chicago, Illinois
2. Department of Medicine, University of Miami Miller School of Medicine, Miami Veterans Affairs Healthcare System, Miami, Florida
3. Department of Pediatrics, Hemby Children's Hospital and Eastover Pediatrics, Charlotte, North Carolina
4. Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
5. Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota
6. Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts
7. Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
8. Respiratory Diseases Branch, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia