Division of Infectious diseases, Department of Pediatric Infectious Diseases, Sainte Justine University Hospital, University of Montreal, Quebec, Canada. Infection, Antimicrobials, Modelling, Evolution, Inserm, UMR 1137, Paris University, Paris, France. Association Clinique et, Thérapeutique Infantile du Val-de-Marne, St Maur-des-Fossés, France. Department of Pediatrics, Harvard Medical School, Boston, Massachusetts. Division of Immunology, Boston Children's Hospital, Boston, Massachusetts. Section of Pediatrics, Division of Infectious Diseases, Department of Medicine, Imperial College London, London, United Kingdom. Hospices Civils de Lyon, Pediatric Nephrology, Rheumatology, Dermatology, Hopital Femme, Mère Enfant, Centre International de Recherche en Infectiologie/INSERM U1111, Bron, France. Department of General Pediatrics, Pediatric Infectious Disease and Internal Medicine, Robert Debré University Hospital, Assistance Publique-Hôpitaux de Paris, Université De Paris, Paris, France. COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia. Department of Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts. Service of Pediatrics, Department Women-Mother-Child, Lausanne University Hospital, Lausanne, Switzerland.