Following the emergence of a novel coronavirus and its spread outside of China, many European countries have implemented unprecedented non-pharmaceutical interventions such as closure of schools and national lockdowns.
This study examines the impact of major interventions across 11 European countries for the period from the start of COVID-19 until the 4th of May 2020 when lockdowns started to be lifted. The authors developed a model that calculates backwards from observed deaths to estimate transmission that occurred several weeks prior, allowing for the time lag between infection and death. They used partial pooling of information between countries with both individual and shared effects on the reproduction number.
They estimate that, for all the countries we consider, current interventions have been sufficient to drive the reproduction number below 1 and achieve epidemic control. They further estimate that, across all 11 countries, between 12 and 15 million individuals have been infected with SARS-CoV-2 up to 4th May, representing between 3.2% and 4.0% of the population. Their results show that major non-pharmaceutical interventions and lockdown in particular have had a large effect on reducing transmission and suggest continued intervention to keep transmission of SARS-CoV-2 under control.