Minal K. Patel, MD1, Laure Dumolard, PhD1, Yoann Nedelec, MPH1, Samir V. Sodha, MD1, Claudia Steulet1, Marta Gacic-Dobo, MSc1, Katrina Kretsinger, MD1, Jeffrey McFarland, MD2, Paul A. Rota, PhD3 and James L. Goodson, MPH21Department of Immunization, Vaccines, and Biologicals, World Health Organization, Geneva, Switzerland; 2Global Immunization Division, Center for Global Health, CDC; 3Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, CDC.Corresponding authorMinal K. Patel, patelm@who.int.All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.