Fig. 4
Effect of SARS-CoV-2 vaccination on antibody presence in breast milk in mothers with previous SARS-CoV-2 infection compared to those without previous exposure. Maternal samples from SARS-CoV-2-positive women (purple) before vaccination and those without viral exposure before vaccination (orange) were analyzed for detection of IgG (A) and IgA (B) antibody levels against RBD SARS-CoV-2. Additionally, samples from pre-pandemic and SARS-CoV-2-positive mothers were included. One-way ANOVA with a Tukey’s post hoc test for multiple comparisons was performed to assess the statistical significance of the differences in the antibody detection. Only those differences between the grouped samples of the vaccinated mothers with previous SARS-CoV-2 infection and all other analyzed groups are shown. The time points shown in the figure are as follows: Post-1st dose and post-2nd dose (21–28 days after 1st dose and 2nd dose, respectively). Data is presented as mean and 95% of CI of the log-transformed arbitrary units (AU). *p <0.05, **p <0.01, ***p <0.001, and **** p <0.0001