1. Research , Evidence and Knowledge Division, , London E14 5EA , UK
2. UK Health Security Agency (UKHSA) , Evidence and Knowledge Division, , London E14 5EA , UK
3. Clinical and Public Health Response Division, UKHSA , London E14 5EA , UK
4. Evaluation and Epidemiological Science Division, UKHSA , Colindale NW9 5EQ , UK
5. Cheshire and Merseyside Health Protection Team, UKHSA , Liverpool L3 1DS , UK
6. Greater Manchester Health Protection Team, UKHSA , Manchester M1 3BN , UK
7. Evaluation and Epidemiological Science Division, UKHSA , Salisbury SP4 0JG , UK
8. Director General Science and Research and Chief Scientific Officer, UKHSA , London E14 5EA , UK