Seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Dutch hospitals after the 2020 first wave: a multicentre cross-sectional study with prospective follow-up oleh Claudia Recanatini, Corine H. GeurtsvanKessel, Suzan D. Pas, Els M. Broens, Martje Maas, Rosa van Mansfeld, Anne J. G. Mutsaers-van Oudheusden, Miranda van Rijen, Emile F. Schippers, Arjan Stegeman, Adriana Tami, Karin Ellen Veldkamp, Hannah Visser, Andreas Voss, Marjolijn C. A. Wegdam-Blans, Heiman F. L. Wertheim, Peter C. Wever, Marion P. G. Koopmans, Jan A. J. W. Kluytmans, Marjolein F. Q. Kluytmans-van den Bergh, COCON Study Group