Public Health England - Immunisation and Countermeasures Division, Public Health England, Government of the United Kingdom - Public Health England Colindale, East London NHS Foundation Trust, Derbyshire Healthcare NHS Foundation Trust, The University of Manchester - Manchester University NHS Foundation Trust, Birmingham Community Healthcare NHS Trust, Oxford University Hospitals NHS Foundation Trust, Oxford University Hospitals NHS Foundation Trust, Government of the United Kingdom - Public Health England Colindale, London School of Hygiene & Tropical Medicine - Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London School of Hygiene and Tropical Medicine, London School of Hygiene and Tropical Medicine, London School of Hygiene and Tropical Medicine, London School of Hygiene & Tropical Medicine - Department of Disease Control, London School of Hygiene & Tropical Medicine - Faculty of Infectious and Tropical Diseases, Office for National Statistics, Office for National Statistics, Public Health England - Immunisation and Countermeasures Division, Public Health England Colindale, Public Health England - Virus Reference Department, Public Health England, Blood Borne Virus Unit, National Infection Service, Colindale Public Health England, Virus Reference Department, Public Health England, Government of the United Kingdom - Public Health England, Public Health England, Office for National Statistics, Public Health England - Immunisation, Hepatitis, and Blood Safety Department and Public Health England - Immunisation and Countermeasures Division

Government of the United Kingdom - Public Health England, UK Health Security Agency, UK Health Security Agency - Emergency Preparedness, Response and Resilience, Government of the United Kingdom - Public Health England, UK Health Security Agency, Government of the United Kingdom - Public Health England, NHSE/I Children and Young People's Transformation Team, affiliation not provided to SSRN, University College London - Great Ormond Street Institute of Child Health, Cedars Sinai Medical Center - Department of Pediatrics, Government of the United Kingdom - Public Health England, UK Health Security Agency, Public Health England - Immunisation and Countermeasures Division, Royal College of Paediatrics and Child Health, University of Southampton - University Hospital Southampton NHS Foundation Trust, University Hospitals Bristol - University Hospitals Bristol and Weston NHS Foundation Trust, St George's University Hospitals NHS Foundation Trust, Birmingham Women’s and Children’s NHS Foundation Trust, Royal College of Paediatrics and Child Health, NHS Foundation Trust - London North West Healthcare NHS Trust, Alder Hey Children's NHS Foundation Trust, Public Health England, University of Bristol, Public Health England - Immunisation, Hepatitis, and Blood Safety Department, University of Liverpool - Health Protection Research Unit in Emerging and Zoonotic Infections, University of Edinburgh - Department of Child Life and Health, Imperial College Healthcare NHS Trust - Paediatric Infectious Diseases Department, Anuerin Bevan University Health Board, Government of the United Kingdom - Public Health Scotland and Public Health England - Immunisation and Countermeasures Division

Public Health England - Immunisation and Countermeasures Division, Public Health England - Immunisation and Countermeasures Division, East London NHS Foundation Trust, Derbyshire Healthcare NHS Foundation Trust, The University of Manchester - Manchester University NHS Foundation Trust, Birmingham Community Healthcare NHS Trust, Oxford University Hospitals NHS Foundation Trust, Oxford University Hospitals NHS Foundation Trust, Public Health England, Public Health England Colindale, Public Health England, Public Health England, Public Health England - Immunisation and Countermeasures Division, Public Health England - Immunisation and Countermeasures Division, Immunisation and Countermeasures Division, Public Health England, Public Health England - Immunisation and Countermeasures Division, Meningococcal Reference Unit, UK Health Security Agency, Public Health England, Manchester Royal Infirmary, Public Health England - Virus Reference Department, Public Health England, Government of the United Kingdom - Immunisation and Countermeasures Division, Public Health England - Immunisation and Countermeasures Division, Public Health England Colindale, Public Health England and Public Health England - Immunisation, Hepatitis, and Blood Safety Department

Government of the United Kingdom - Public Health England Colindale, Public Health England, Government of the United Kingdom - Public Health England Colindale, East London NHS Foundation Trust, Government of the United Kingdom - Public Health England Colindale, The University of Manchester - Manchester University NHS Foundation Trust, Birmingham Community Healthcare NHS Trust, Oxford University Hospitals NHS Foundation Trust, Oxford University Hospitals NHS Foundation Trust, Meningococcal Reference Unit, UK Health Security Agency, Public Health England, Manchester Royal Infirmary, UK Health Security Agency, UK Health Security Agency, Public Health England - Virus Reference Department, Public Health England, Government of the United Kingdom - Public Health England, Public Health England - Immunisation and Countermeasures Division, UK Health Security Agency, Public Health England - Immunisation, Hepatitis, and Blood Safety Department, Government of the United Kingdom - Public Health England Colindale and Government of the United Kingdom - Immunisation and Countermeasures Division