Figure 5. Cross-responses of neutralizing antibodies to Omicron in vaccinated 2-year convalescents and healthy controls.
A, Competitive inhibition of anti-RBD neutralizing antibodies against Wild Type (WT) (red, n=23), Delta (blue, n=23), BA.1 (green, n=23), BA.2 (purple, n=23), and BA.4/5 (pink, n=23) was measured at 6-month, 1-year, and 2-year convalescent individuals after symptoms onset. B, Comparison of the inhibition levels of neutralizing antibodies against the above five strains for HC-Unvac (yellow, n=26), HC-Vac (purple, n=35), and 2Y-Vac (red, n=51) groups. C-D, Changes of neutralization capacity toward WT (red), Delta (blue), BA.1 (green), BA.2 (purple), and BA.4/5 (pink) were detected using sera from vaccinated 2-year convalescents (2Y-Vac, n=51) (C) and healthy controls after vaccination (HC-Vac, n=35) (D). Pie charts summarized the positive inhibition ratios of neutralizing antibodies (NAb) against different strains. E, NAb inhibition rates against four SARS-CoV-2 variants (Delta, BA.1, BA.2, and BA.4/5) were normalized using the geometric mean ratio of NAb inhibition rates versus WT (HC-Vac: orange; 2Y-Vac: blue). F, The seropositivity of neutralizing antibodies, in 2Y-Vac and HC-Vac individuals, identified in naught (no response, white), one (WT, yellow), two (WT + Delta, purple), three (WT + Delta + BA.2, blue), four (WT + Delta + BA.1/2, green) or five (WT + Delta + BA.1/2/4/5, red) strains. Each dot represents a unique donor. Black dotted lines and bars represent the threshold for positive and medians of responders. Significance was assessed using the Wilcoxon matched-pairs signed rank test (A, C, D) and Mann-Whitney U-test (B). * p < 0.05, ** p < 0.01, *** p < 0.001.