1. Jeffrey S. Gerber is an associate professor of Pediatrics and Epidemiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA and deputy director of the Center for Pediatric Clinical Effectiveness at Children’s Hospital of Philadelphia, Philadelphia, PA, USA.
2. Paul A. Offit is the director of the Vaccine Education Center in the Division of Infectious Diseases at Children’s Hospital of Philadelphia, Philadelphia, PA, USA and a professor in the Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.