Fig. 6.

Humoral responses to SARS-CoV-2 vaccination and Omicron infections. In Panel A, post-vaccination neutralizing antibodies against ancestral SARS-CoV-2 were measured after two and three mRNA vaccine doses and prior to future Omicron BA.1/2 and BA.5 infection outcomes. Humoral responses were examined in Panels B to D in serum samples collected after the observation period baseline and Omicron BA.5 infections. Ancestral anti-spike and anti-RBD (receptor binding domain) IgG and IgA antibody levels were measured by ELISA. Neutralizing antibodies against ancestral and Omicron BA.1 anti-SARS-CoV-2 were assessed by microneutralization assays (MNT₅₀). Each data point indicates an individual participant. Data are presented as box and whisker plots, minimum to maximum, with the center line at the median. Data in Panels A and B are presented on a log2 scale. Dotted lines indicate cutoff thresholds. Statistical significance was assessed by Kruskal–Wallis test with Dunn's multiple comparisons test. P values are only shown for post-hoc comparisons of statistical significance.