Figure 1.

Antibody responses for the four overlapping pools of peptide of the N protein of SARS-CoV-2. IgG antibody responses were measured by an in-house ELISA for pool 1 (A), pool 2 (B), pool 3 (C), and pool 4 (D) containing overlapping peptides of the N protein in SARS-CoV-2 seronegative (non-vaccinated) individuals (n = 30), WT infected individuals (n = 30), delta infected individuals (n = 30), omicron infected and vaccinated individuals (n = 20), and Sinopharm vaccinees (n = 30). Kruskal–Wallis test was used to determine the differences between the levels of antibody responses in four peptide pools (pools 1, 2, 3, and 4). The dotted line shows the cutoff value (OD value) of a positive response for the each of the peptide pools. The error bars indicate the median and the interquartile ranges.