European governments employed non-pharmaceutical interventions (NPIs) to curb resurging COVID-19 waves. This study estimates the effectiveness of 17 NPIs during Europe's second wave using subnational case and death data, a flexible hierarchical Bayesian transmission model, and a comprehensive dataset of NPI implementation dates. While business closures, educational institution closures, and gathering bans reduced transmission, their impact was less pronounced than in the first wave, likely due to organizational safety measures and individual protective behaviors. Second-wave estimates proved superior to previous ones in predicting transmission during the third wave.

Mrinank Sharma, Sören Mindermann, Charlie Rogers-Smith, Gavin Leech, Benedict Snodin, Janvi Ahuja, Jonas B. Sandbrink, Joshua Teperowski Monrad, George Altman, Gurpreet Dhaliwal, Lukas Finnveden, Alexander John Norman, Sebastian B. Oehm, Julia Fabienne Sandkühler, Laurence Aitchison, Tomáš Gavenčiak, Thomas Mellan, Jan Kulveit, Leonid Chindelevitch, Seth Flaxman, Yarin Gal, Swapnil Mishra, Samir Bhatt, Jan Markus Brauner