Fig. 6.
Neutralizing antibody titer after BA.2 breakthrough infection and the fourth vaccination.(a–e) The neutralizing antibody (IC50 represents serum dilution required to achieve 50% virus neutralization) against five SARS-CoV-2 strains were measured by pseudovirus-based assay among uninfected and infected 3 × BNT (orange), 3 × CorV (blue), 2 × CorV+1 × BNT (purple) and 3 × CorV+1 × BNT (grey) before (empty dots) and after (solid dots) BA.2 infection or the fourth vaccination. Black dots and lines represent the breakthrough infection sample in each group. Numbers on the figure top indicate the fold-change in NAb titer between samples collected before and after BA.2 infection or the fourth vaccination. Numbers under the x-axis indicate the geometric mean titers (GMT). Statistics were generated by using 2-tailed Student's t test. ∗p < 0.05; ∗∗∗p < 0.001; ns: not significant.