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[Preprint]. 2020 Sep 25:2020.09.22.20192443. [Version 1] doi: 10.1101/2020.09.22.20192443

Figure 3. Anti-SARS-CoV-2 serologies and neutralizing antibodies.

Figure 3.

Plasma samples were analyzed by ELISA at a 1:100 dilution for the presence of IgG, IgA and IgM antibodies binding to the SARS-CoV-2 spike (Panel A), nucleocapsid (Panel B), and RBD (Panel C) antigens. Panel D shows the results of testing for antibodies that block the binding of ACE2 to RBD, carried out with a 1:10 dilution of plasma (left y-axis). Pseudovirus neutralizing antibodies were detected with in vitro cell culture assay with D614 (Wuhan) pseudovirus and D614G pseudovirus (right y-axis). For all panels, time on the x-axis indicates days after symptom onset during SARS-CoV-2 reinfection. Plasma pools from SARS-CoV-2 pre-pandemic healthy blood donors and from primary infection COVID-19 patients were used as negative and positive quality control (QC), respectively. The dotted line is the cutoff value for a positive result for each assay, determined as described in the Supplemental Methods. All samples were tested in duplicate wells, and mean OD values are shown. Results are shown from one of two replicate experiments carried out on different days.