The 2020 SARS-CoV-2 epidemic in England: key epidemiological drivers and impact of interventions

Knock, E. S.; Whittles, L. K.; Lees, J. A.; Perez-Guzman, P. N.; Verity, R.; FitzJohn, R. G.; Gaythorpe, K. A.; Imai, N.; Hinsley, W.; Okell, L. C.; Rosello, A.; Kantas, N.; Walters, C. E.; Bhatia, S.; Watson, O. J.; Whittaker, C.; Cattarino, L.; Boonyasiri, A.; Djaafara, B. A.; Fraser, K.; Fu, H.; Wang, H.; Xi, X.; Donnelly, C. A.; Jauneikaite, E.; Laydon, D. J.; White, P. J.; Ghani, A. C.; Ferguson, N. M.; Cori, A.; Baguelin, M.

We fitted a model of SARS-CoV-2 transmission in care homes and the community to regional surveillance data for England. Among control measures implemented, only national lockdown brought the reproduction number below 1 consistently; introduced one week earlier it could have reduced first wave deaths from 36,700 to 15,700 (95%CrI: 8,900-26,800). Improved clinical care reduced the infection fatality ratio from 1.25% (95%CrI: 1.18%-1.33%) to 0.77% (95%CrI: 0.71%-0.84%). The infection fatality ratio was higher in the elderly residing in care homes (35.9%, 95%CrI: 29.1%-43.4%) than those residing in the community (10.4%, 95%CrI: 9.1%-11.5%). England is still far from herd immunity, with regional cumulative infection incidence to 1st December 2020 between 4.8% (95%CrI: 4.4%-5.1%) and 15.4% (95%CrI: 14.9%-15.9%) of the population.