SARS-CoV-2 immunity and reasons for non-vaccination among healthcare workers from eastern and northern Switzerland: results from a nested multicentre cross-sectional study oleh Selina Albrecht, Fabian Grässli, Alexia Cusini, Angela Brucher, Stephan Goppel, Elsbeth Betschon, J. Carsten Möller, Manuela Ortner, Markus Ruetti, Reto Stocker, Danielle Vuichard-Gysin, Ulrike Besold, Lorenz Risch, Matthias von Kietzell, Matthias Schlegel, Pietro Vernazza, Stefan P. Kuster, Christian R. Kahlert, Philipp Kohler