Figure 1. Neutralizing activity of maternal and cord plasma samples from the vaccination cohort and infection cohort.

(A) Comparison of the mean NT₅₀ titers against all examined strains between the vaccinated (n = 30) and infected (n = 26) groups. The dot plots show mean NT₅₀ values against variants of each patient in maternal plasma and cord plasma. Black bars represent the median of mean NT₅₀ values. (B and C) Mean NT₅₀ values of the maternal and cord blood were compared by 3 trimesters separately. The dot plots show mean NT₅₀ values against all variants of each patient. Black bars represent the median of mean NT₅₀ values. (D and E) Comparison of the NT₅₀ values by trimester and by 5 strains in the maternal blood (D) and cord blood (E). The dot plots show NT₅₀ values against each variant (vaccinated group: n = 30 for the WT strain and the Alpha, Kappa, Delta, and Mu variants; infected group: n = 30 for the WT strain and the Alpha and Kappa variants, n = 27 for the Delta variant, and n = 26 for the Mu variant). Black bars represent the median of NT₅₀ values. The dotted lines indicate the cutoff threshold of this assay. Trimester of exposure is indicated by color (red, first trimester; blue, second trimester; yellow, third trimester). *P < 0.05; **P < 0.01; *** P < 0.001; ****P < 0.0001 by Mann-Whitney U test or Friedman’s test with Dunn’s multiple comparisons.