Comparison of two antibody screening systems for SARS-CoV-2 antibody detection in recovered and vaccinated subjects - test performance and possible indicators for immunity.

Background: Detection of seroconversion after SARS-CoV-2-infection or vaccination is relevant to discover subclinical cases and recognize patients with a possible immunity.

Objectives: Test performance, effects of age, time-point of seroconversion and immune status regarding neutralizing antibodies (NAbs) and T-cell-reactivity were investigated.

Study Design: Two antibody assays (Viramed-Test for S/N-specific IgG, Roche-Test for N-specific IgA, -M, -G) were evaluated with classified samples.