Affiliation

• ¹ From the *Paediatric Infectious Diseases Research Group, St George's University, London, United Kingdom; †Centre for Virology, University College Medical School, London; ‡Kingston Hospital NHS Foundation Trust, London, United Kingdom; §The Hague Medical Center (HMC), Department of Pediatrics and Sophia Children's hospital, Erasmus Medical Center Rotterdam Department of Pediatric Infectious Diseases; ¶Pediatric Infectious Diseases Unit, Hospital Universitario 12 de Octubre, Universidad Complutense, Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain; ∥Center for Chronic Immunodeficiency and Center for Pediatrics and Adolescent Medicine, Medical Center and Faculty of Medicine, University of Freiburg, Germany; **Our Lady's Children's Hospital Crumlin, UCD School of Medicine and Health Sciences, Dublin, Ireland; ††Department of Obstetrical, Gynaecological and Paediatric Sciences, Operative Unit of Neonatology, Polyclinic St. Orsola-Malpighi, University of Bologna, Bologna, Italy; ‡‡Pediatric Infectious Diseases, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain; §§Department of Paediatrics, The University of Melbourne & Murdoch Children's Research Institute, Royal Children's Hospital Melbourne, Parkville, Australia; ¶¶NICU and Neonatal Unit, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy; ∥∥Infectious Diseases Unit, 3rd Department of Pediatrics, Faculty of Medicine, Aristotle University School of Health Sciences, Thessaloniki, Greece; ***Great Ormond Street Children's Hospital, London, and the Institute of Child Health, UCL, London, United Kingdom; †††NICU and Neonatal Unit, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy; ‡‡‡Imperial College NHS Healthcare, London, United Kingdom; §§Pediatric Infectious Diseases, Children's Hospital, University of Helsinki and Helsinki University Hospital, Finland; ¶¶¶Department of Pediatric Infectious Diseases, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands; ∥∥∥National and Kapodistrian University of Athens, Greece; ****Children's Hospital of Geneva, University Hospitals of Geneva, Switzerland; ††††Pediatric Infectious Diseases Unit, Gregorio Marañón Hospital, Madrid, Spain; and ‡‡‡‡Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.