Fig. 1.

Antibody responses in seronegative (A) and seropositive (B) HCWs after mRNA-1273 vaccination.

It shows the titers of SARS-CoV-2 IgG antibodies directed against the subunits (S1) and (S2) of the virus spike protein before (T0), 2 weeks after the first injection (T1), 2 weeks after the second injection (T2) and 3 months after the first infection (T3) according to the participant serological status (n = 205). The Box-and-Whisker plot represents the 25th and 75th percentiles. Inside the box, the horizontal line indicates the median (the 50th percentile). Discs in light grey represent far out values. A Wilcoxon test was used to assess the changes in IgG levels between T0, T1, T2 and T3 times within seronegative (n = 161) and seropositive subjects (n = 44). A P-value < 0.05 was considered significant.