1. University of Pittsburgh School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Disease, Pittsburgh, Pennsylvania, USA
2. University of Pittsburgh Center for Vaccine Research, Pittsburgh, Pennsylvania, USA
3. University of Pittsburgh, UPMC Children’s Hospital, Pittsburgh, Pennsylvania, USA
4. Centers for Disease Control and Prevention, Viral Special Pathogens Branch, Atlanta, Georgia, USA
5. Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, USA
6. Department of Medicine, Division of Infectious Diseases and Global Public Health, University of California, San Diego, La Jolla, California, USA