1 Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium, and the Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium.
2 St. Giles Laboratory of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, New York, USA; the Howard Hughes Medical Institute, New York, New York, USA; the Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Necker Hospital for Sick Children, Paris, France; the Imagine Institute, Paris Descartes University, Paris, France; and the Pediatric Hematology and Immunology Unit, Assistance Publique-Hôpitaux de Paris, Necker Hospital for Sick Children, Paris, France.