External quality assessment of SARS-CoV-2 serology in European expert laboratories, April 2021 Mögling, Ramona and Colavita, Francesca and Reimerink, Johan and Melidou, Angeliki and Leitmeyer, Katrin and Keramarou, Maria and Lapa, Daniele and Francalancia, Massimo and Murk, Jean-Luc and Vossen, Ann and Carletti, Fabrizio and Hogema, Boris and Meijer, Adam and Deprez, Liesbet and di Caro, Antonino and Castilletti, Concetta and Reusken, Chantal BEM, Eurosurveillance, 27, 2101057 (2022), https://doi.org/10.2807/1560-7917.ES.2022.27.42.2101057