Key epidemiological drivers and impact of interventions in the 2020 SARS-CoV-2 epidemic in England
Edward Knock, Lilith K. Whittles, John A. Lees, Pablo N. Perez‐Guzman, Robert Verity, Richard G. FitzJohn, Katy A. M. Gaythorpe, Natsuko Imai, Wes Hinsley, Lucy Okell, Alicia Roselló, Nikolas Kantas, Caroline E. Walters, Sangeeta Bhatia, Oliver J. Watson, Charles Whittaker, Lorenzo Cattarino, Adhiratha Boonyasiri, Bimandra A Djaafara, Keith Fraser, Han Fu, Haowei Wang, Xiaoyue Xi, Christl A. Donnelly, Elita Jauneikaite, Daniel J. Laydon, Peter J White, Azra C. Ghani, Neil M. Ferguson, Anne Cori, Marc Baguelin
Abstract
) below 1 consistently; if introduced 1 week earlier, it could have reduced deaths in the first wave from an estimated 48,600 to 25,600 [95% credible interval (CrI): 15,900 to 38,400]. The infection fatality ratio decreased from 1.00% (95% CrI: 0.85 to 1.21%) to 0.79% (95% CrI: 0.63 to 0.99%), suggesting improved clinical care. The infection fatality ratio was higher in the elderly residing in care homes (23.3%, 95% CrI: 14.7 to 35.2%) than those residing in the community (7.9%, 95% CrI: 5.9 to 10.3%). On 2 December 2020, England was still far from herd immunity, with regional cumulative infection incidence between 7.6% (95% CrI: 5.4 to 10.2%) and 22.3% (95% CrI: 19.4 to 25.4%) of the population. Therefore, any vaccination campaign will need to achieve high coverage and a high degree of protection in vaccinated individuals to allow nonpharmaceutical interventions to be lifted without a resurgence of transmission.