SARS-CoV-2 infection and transmission in school settings during the second COVID-19 wave: a cross-sectional study, Berlin, Germany, November 2020 Theuring, Stefanie and Thielecke, Marlene and van Loon, Welmoed and Hommes, Franziska and Hülso, Claudia and von der Haar, Annkathrin and Körner, Jennifer and Schmidt, Michael and Böhringer, Falko and Mall, Marcus A and Rosen, Alexander and von Kalle, Christof and Kirchberger, Valerie and Kurth, Tobias and Seybold, Joachim and Mockenhaupt, Frank P and BECOSS Study Group, Eurosurveillance, 26, 2100184 (2021), https://doi.org/10.2807/1560-7917.ES.2021.26.34.2100184