Understanding the effectiveness of government interventions against the resurgence of COVID-19 in Europe

TLDR

European governments use non‑pharmaceutical interventions to curb resurging COVID‑19 waves, yet they rely on outdated effectiveness estimates from the first wave. This study estimates the effectiveness of 17 interventions during Europe’s second wave and compares them to the first wave to guide future pandemic policy. The authors employ a flexible hierarchical Bayesian transmission model applied to subnational case and death data, supported by the largest compiled dataset of NPI implementation dates across Europe. Business closures, school closures, and gathering bans lowered transmission in the second wave, but less than in the first wave, likely due to enhanced safety measures and distancing, and the second‑wave estimates better predict third‑wave transmission.

Abstract

European governments control resurging waves of COVID-19 using nonpharmaceutical interventions. Here, the authors estimate the effectiveness of 17 interventions in Europe's second wave, and analyse differences to the first wave as well as implications for the future of the pandemic. European governments use non-pharmaceutical interventions (NPIs) to control resurging waves of COVID-19. However, they only have outdated estimates for how effective individual NPIs were in the first wave. We estimate the effectiveness of 17 NPIs in Europe's second wave from subnational case and death data by introducing a flexible hierarchical Bayesian transmission model and collecting the largest dataset of NPI implementation dates across Europe. Business closures, educational institution closures, and gathering bans reduced transmission, but reduced it less than they did in the first wave. This difference is likely due to organisational safety measures and individual protective behaviours-such as distancing-which made various areas of public life safer and thereby reduced the effect of closing them. Specifically, we find smaller effects for closing educational institutions, suggesting that stringent safety measures made schools safer compared to the first wave. Second-wave estimates outperform previous estimates at predicting transmission in Europe's third wave.