Figure 2.

Viral microneutralization assay against omicron sublineages to evaluate neutralization titers (VNT₅₀) and seroconvertion rate. (A) VNT₅₀ for samples collected 9 months after CoronaVac 2 doses protocol. (B) VNT₅₀ for samples collected 12 months after CoronaVac 2 doses protocol; (C) VNT₅₀ for samples collected 18 months after CoronaVac 2 doses protocol. Vaccination subgroups are represented in green (No booster), blue (1 booster) and pink (2 boosters). VNT₅₀ means, for each group, are highlighted under the graphs. Dashed lines represent the seroconvertion dilution cutoff (1:20), while seroconvertion rates are defined as percentages. The significance lines represent the differences among the mean neutralization titers of the groups. It was considered p-values lower than 0.05 for the significance. One asterisk (*) = p-value < 0.05; two asterisks (**) = p-value < 0.01; and three asterisks (***) = p-value < 0.001.