1 Department of Paediatrics, The University of Melbourne, Parkville, Australia; Infectious Diseases Unit, The Royal Children's Hospital Melbourne, Parkville, Australia; Infectious Diseases & Microbiology Group, Murdoch Children's Research Institute, Parkville, Australia. Electronic address: nigel.curtis@rch.org.au.
2 Department of Paediatrics, University of Oxford, Oxford, UK; Children's Hospital Oxford, Oxford, UK. Electronic address: andrew.pollard@paediatrics.ox.ac.uk.
3 School of Clinical Sciences and School of Cellular & Molecular Medicine, University of Bristol, Bristol, UK; Bristol Children's Vaccine Centre, Bristol, UK; University Hospitals Bristol NHS Foundation Trust, Bristol, UK. Electronic address: adam.finn@bristol.ac.uk.
4 The Ohio State University College of Medicine, Columbus, OH, USA; Division of Infectious Diseases, Nationwide Children's Hospital, OH, USA. Electronic address: Octavio.Ramilo@nationwidechildrens.org.
5 Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada; Division of Pediatric Infectious Diseases, BC Children's Hospital, Vancouver, BC, Canada. Electronic address: sdobson@cw.bc.ca.
6 Institute of Medical Sciences University of Aberdeen Royal Aberdeen Children's Hospital, Aberdeen, Scotland, UK. Electronic address: a.warris@abdn.ac.uk.
7 Division of Pediatric Infectious Diseases, Immunology and Rheumatology, Department of Pediatrics, Erasmus MC University Medical Center Rotterdam, The Netherlands. Electronic address: a.vanrossum@erasmusmc.nl.