Figure 3.

Temporal profile of antibodies in patient 1 with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection. Each antibody was measured at 7 time points. A, IgG antibodies against SARS-CoV-2 S1 (blue) and receptor binding domain (green) protein. The cutoff values for IgG antibody assay were S/CO = 1. B, PRNT titers of neutralizing antibody. A PRNT₅₀ titer was defined as the highest serum dilution that results in a reduction of >50% of the control plaque count. A PRNT₅₀ titer of ≥10 was considered protective. Abbreviations: IgG, immunoglobulin G; PRNT, plaque-reduction neutralization test; rRT-PCR, real-time reverse-transcription polymerase chain reaction; S/CO, signal to cutoff. *No intact viral genome was observed at third admission.