For the determination of diagnostic sensitivity, 49 sera from individuals with PCR-confirmed SARS-Cov-2 infection were used. For the determination of specificity, 96 blood samples from blood donors from the previous year, which are usually expected to be negative, were tested. The sensitivity was 95.7% and the specificity was 100%. In a dilution series, the detection limit of the EuroImmune anti-S1 IgG ELISA was 10-fold lower than that of the WANTAI test. The test appears suitable for reliable use in seroprevalence studies. However, to analyze populations with low seroprevalence (<5%) and for individual immunity testing, the high specificity would need to be confirmed on at least another 200 negative samples from the previous year. WANTAI SARS-CoV-2 Ab Rapid Test is a single use device for a qualitative detection of SARS-CoV-2-specific antibodies in human serum, plasma or whole blood. We evaluated the performance of the kit using plasma samples from 96 blood donors who donated blood in summer 2019 (pre-SARS-CoV-2-period) and 49 plasma samples from patients with PCR-confirmed SARS-CoV-2 infection. Moreover, the plasma samples from the latter group were antibody positive in one or more of the serological assays from Euroimmun (anti-SARS-CoV-2-IgA, anti-SARS-CoV-2 -IgG) or Abbott (SARS-CoV-2 IgG immunoassay). The sensitivity was 95.7% and the specificity 100%. The limit of detection is higher than an ELISA-based serological assay (Euroimmun) (1:1000 vs 1:100).

W. BORENA* ⁽¹⁾, N. SCHEDLER ⁽¹), M. HUBER ⁽¹), F. ALLERBERGER ⁽²), D. VON LAER ^{(1) 1} Medical University of Innsbruck ² Austrian Agency for Health and Food Safety GmbH (AGES) *wegene.borena@i-med.ac.at