Fig. 3.

Dynamics of IgG anti-S levels geometric means over time Vertical bars correspond to 25–75 % percentiles and are crossed by the dashed line at the mean. Each circles represents a single individual measurement. Sera were diluted x20 since anti-S levels were over the assay's threshold of 400AU/ml for all participants in the 5th time point (after the third vaccine dose), and for some participants in the 6th time point. Antibody levels at the last, 6th, measurement were significantly higher than at measurements 1–4, p < 0.001. There was a significant difference in IgG anti-S levels between all consecutive measurements, p < 0.001.