1. Paediatric Immunology and Infectious Diseases, Evelina London Children’s Hospital , London , United Kingdom
2. University College London Great Ormond Street Institute of Child Health , London , United Kingdom
3. School of Life Course and Population Sciences, King’s College London , London , United Kingdom
4. Paediatric Intensive Care Unit, Evelina London Children’s Hospital , London , United Kingdom
5. General Paediatrics Department, Evelina London Children’s Hospital , London , United Kingdom
6. Faculty of Life Sciences and Medicine, King’s College London , London , United Kingdom
7. Immunisation Division, UK Health Security Agency , London , United Kingdom
8. Paediatric Infectious Diseases Research Group, St George’s University of London , London , United Kingdom