Transmission dynamics of the COVID-19 epidemic in England

BACKGROUND: The ongoing coronavirus disease 2019 (COVID-19) pandemic has caused a tremendous health burden and impact on the world economy. The UK Government implemented the biggest lockdown of society during peacetime in British history at the end of March 2020, aiming to contain the rapid spread of the virus. The UK lockdown was maintained for 7 weeks, but the effectiveness of the control measures in suppressing disease transmission remains incompletely understood. METHODS: A Bayesian SEIR (susceptible–exposed–infected–removed) epidemiological model was used to rebuild the local transmission dynamics of the spread of COVID-19 in nine regions of England. RESULTS: The basic reproduction number (R(0)) in England was found to be relatively high compared with China. The estimate of the temporally varying effective reproduction number (R(t)) suggests that the control measures, especially the forced lockdown, were effective to reduce transmissibility and curb the COVID-19 epidemic. Although the overall incidence rate in the UK has declined, forecasting highlights the possibility of a second epidemic wave in several regions. CONCLUSION: This study enhances understanding of the current outbreak and the effectiveness of control measures in the UK.