Fig. 2.

Evolution of (A) anti-RBD (anti-receptor binding domain of viral spike protein), (B) anti-N (anti-viral nucleoprotein), and (C) surrogate virus neutralization assay (sVNT) between 1, 3 and 6 months following infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COI, cut-off index; RT-PCR, reverse-transcription polymerase chain reaction. The bars represent the geometric mean concentration (GMC) with 95% confidence interval. The dashed lines represent the respective assays cut-offs.