1. Institute of Immunity and Transplantation, Division of Infection & Immunity, School of Life and Medical Sciences, University College London, Royal Free Hospital, London, United Kingdom;
2. Immunology Department, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom;
3. Papworth and Addenbrooke’s Hospital NHS Foundation Trusts, Cambridge, United Kingdom;
4. Clinical Immunology Department, Royal Free Hospital, London, United Kingdom;
5. Sección de Infectología e Inmunopatología, Unidad de Pediatría, Hospital Virgen del Rocío/Instituto de Biomedicina de Sevilla (IBiS), Sevilla, Spain;
6. Primary Immunodeficiency Group, Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom; and
7. Department of Immunology, University of Manchester, Royal Manchester Children’s Hospital, Manchester, United Kingdom