From the Department of Infectious Disease, Section of Pediatric Infectious Disease (A.J.M., O.V., H.P., E.G.S., P.S., C.W., C.B., R.N., T.D., E.W., J.A.H., M.K., A.J.C., M.L.), and the Inflammation, Repair, and Development Section, National Heart and Lung Institute, Faculty of Medicine (D.M.), Imperial College London, the Department of Pediatrics, Imperial College Healthcare NHS Trust (R.N., E.W., J.A.H., A.J.C., M.L.), and the Department of Women and Children's Health, School of Life Course Sciences, King's College London, St. Thomas' Hospital (M.J.C.), London, and the Genomic Informatics Group, University of Southampton, Southampton (E.G.S.) - all in the United Kingdom; the Translational Genomics Group, Broad Institute of MIT and Harvard, Cambridge, MA (E.G.S.); the Department of Pediatrics, University of California, San Diego, and Rady Children's Hospital, San Diego (A.H.T.); the Department of Pediatrics and Pediatric Infectious Diseases, Sechenov University, Moscow (D.M.); Servicio de Infectología, Hospital Nacional de Niños Dr. Carlos Sáenz Herrera, Centro de Ciencias Médicas, Caja Costarricense de Seguro Social, San José, Costa Rica (R.U.-G.); and the Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York (C.H.).