1 Immunisations and Vaccine Preventable Diseases Division, UK Health Security Agency, 61 Colindale Avenue, London NW9 5EQ, United Kingdom.
2 Division of Surgery & Interventional Science, Faculty of Medical Sciences, University College London, WC1E 6BT, United Kingdom.
3 UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, United Kingdom.
4 Department of Psychiatry, University of Cambridge, Hershel Smith Building Cambridge Biomedical Campus, CB2 0SZ, United Kingdom.
5 Research Department of Primary Care & Population Health, University College London Medical School London United Kingdom.
6 Department of Paediatric Infectious Diseases, Imperial College Healthcare NHS Trust, London, United Kingdom.
7 Paediatric and Adolescent Division, University College London Hospitals NHS Foundation Trust, London, United Kingdom.
8 Immunisations and Vaccine Preventable Diseases Division, UK Health Security Agency, 61 Colindale Avenue, London NW9 5EQ, United Kingdom; Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London, SW17 0RE, United Kingdom. Electronic address: [email protected].