Annabelle de St Maurice1, Kathryn M Edwards2. 1. Division of Infectious Diseases, Department of Pediatrics, Vanderbilt Vaccine Research Program, Vanderbilt University School of Medicine, Nashville, Tennessee. 2. Division of Infectious Diseases, Department of Pediatrics, Vanderbilt Vaccine Research Program, Vanderbilt University School of Medicine, Nashville, Tennessee. Electronic address: kathryn.edwards@vanderbilt.edu.