RT Journal Article SR Electronic(1) A1 Olbrich, Laura A1 Castelletti, Noemi A1 Schälte, Yannik A1 Garí, Mercè A1 Pütz, Peter A1 Bakuli, Abhishek A1 Pritsch, Michael A1 Kroidl, Inge A1 Saathoff, Elmar A1 Guggenbuehl Noller, Jessica Michelle A1 Fingerle, Volker A1 Le Gleut, Ronan A1 Gilberg, Leonard A1 Brand, Isabel A1 Falk, Philine A1 Markgraf, Alisa A1 Deák, Flora A1 Riess, Friedrich A1 Diefenbach, Max A1 Eser, Tabea A1 Weinauer, Franz A1 Martin, Silke A1 Quenzel, Ernst-Markus A1 Becker, Marc A1 Durner, Jürgen A1 Girl, Philipp A1 Müller, Katharina A1 Radon, Katja A1 Fuchs, Christiane A1 Wölfel, Roman A1 Hasenauer, Jan A1 Hoelscher, Michael A1 Wieser, Andreas A1 on behalf of the KoCo19-Study GroupYR 2021 T1 Head-to-head evaluation of seven different seroassays including direct viral neutralisation in a representative cohort for SARS-CoV-2 JF Journal of General Virology, VO 102 IS 10 OP SP 001653 DO https://doi.org/10.1099/jgv.0.001653 PB Microbiology Society, SN 1465-2099, AB A number of seroassays are available for SARS-CoV-2 testing; yet, head-to-head evaluations of different testing principles are limited, especially using raw values rather than categorical data. In addition, identifying correlates of protection is of utmost importance, and comparisons of available testing systems with functional assays, such as direct viral neutralisation, are needed.We analysed 6658 samples consisting of true-positives (n=193), true-negatives (n=1091), and specimens of unknown status (n=5374). For primary testing, we used Euroimmun-Anti-SARS-CoV-2-ELISA-IgA/IgG and Roche-Elecsys-Anti-SARS-CoV-2. Subsequently virus-neutralisation, GeneScriptcPass, VIRAMED-SARS-CoV-2-ViraChip, and Mikrogen-recomLine-SARS-CoV-2-IgG were applied for confirmatory testing. Statistical modelling generated optimised assay cut-off thresholds. Sensitivity of Euroimmun-anti-S1-IgA was 64.8%, specificity 93.3% (manufacturer’s cut-off); for Euroimmun-anti-S1-IgG, sensitivity was 77.2/79.8% (manufacturer’s/optimised cut-offs), specificity 98.0/97.8%; Roche-anti-N sensitivity was 85.5/88.6%, specificity 99.8/99.7%. In true-positives, mean and median Euroimmun-anti-S1-IgA and -IgG titres decreased 30/90 days after RT-PCR-positivity, Roche-anti-N titres decreased significantly later. Virus-neutralisation was 80.6% sensitive, 100.0% specific (≥1:5 dilution). Neutralisation surrogate tests (GeneScriptcPass, Mikrogen-recomLine-RBD) were >94.9% sensitive and >98.1% specific. Optimised cut-offs improved test performances of several tests. Confirmatory testing with virus-neutralisation might be complemented with GeneScriptcPassTM or recomLine-RBD for certain applications. Head-to-head comparisons given here aim to contribute to the refinement of testing strategies for individual and public health use., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.001653