Fig. 2.

Convalescent plasma donation testing for SARS-CoV-2 nAbs using EliA S1-IgG (A) and ACE2 receptor binding inhibition assay (B) methods, plotted against the number of days post-positive PCR test. Each donor is shown in a different colour, and colours are preserved between graphs. Datapoints for each donor (that is, donations) were fitted using a one-phase decay exponential regression, which allowed for the derivation of the half-life of SARS-CoV-2-related antibodies to be calculated in each case. Exceptionally high EliA S1-IgG results were observed for initial donations from donor #24 (pink), and are therefore called out as an inset to A. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

ACE2, angiotensin-converting enzyme 2; Ig, immunoglobulin; IgG, immunoglobulin G; nAb, neutralising antibody; S1, spike 1; SD, standard deviation.