1. Department of Paediatrics, Oxford University Hospitals NHS Foundation Trust , Oxford , UK
2. Department of Infectious Disease, Imperial College London , London , UK
3. School of Medicine, St Mary’s Hospital , Praed Street London W2 1NY, UK
4. Department of Paediatric Infectious Diseases and Immunology, University Hospital Southampton NHS Foundation Trust , Tremona Road , Southampton SO16 6YD, UK
5. Centre for Cancer Immunology, University of Southampton and Department of Paediatric Oncology, University Hospital Southampton NHS Foundation Trust , Southampton SO17 1BJ , UK