FIGURE 2.

Potent binding and neutralizing antibodies against SARS‐CoV‐2 variants induced by a third dose of inactivated vaccine. (A) ELISA binding of 113 donors at three follow‐up visits to SARS‐CoV‐2 WT and mutated RBD proteins. Plasma samples were tested at a dilution of 1:20. ELISA, enzyme‐linked immunosorbent assay; O.D., optical density. (B) Neutralizing activities of 113 donors at three follow‐up visits against SARS‐CoV‐2 WT, beta, delta, and lambda variants. The inhibition of 50% is indicated by a horizontal dashed line. (C) Correlation analysis between binding and neutralizing activities against SARS‐CoV‐2 WT and variants of 113 donors at three follow‐up visits. The correlation was analysed using GraphPad Prism 8.0 software by linear regression model. ‘+’ indicates increased binding or neutralizing activity, ‘–’ indicates decreased binding or neutralizing activity. ‘X’ indicates fold change. *p < .05; **p < .01; ****p < .0001; ns, not significant