In the following, we present data on the diagnostic performance of eight commercially available SARS-CoV-2 IgG or total SARS-CoV-2 antibody tests. Variations in their diagnostic sensitivity and specificity were observed. In terms of their performance, two IgG assays using the N or S proteins of SARS-CoV-2 were selected for an analysis of follow-up sera to obtain data on the kinetics of IgG. The development of IgG avidities and the kinetics of SARS-CoV-2-neutralizing antibodies were also examined over time.