From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St.... (At 2022-04-21)