Fig. 2
Effect of vaccination on IgG and IgA found in breast milk according to the administered vaccines in Spain. A, B Trajectories of the anti-SARS-CoV-2 IgG (A) and IgA (B) in breast milk samples according to vaccine type from baseline (before the 1st dose) to 4 weeks post-vaccination course. The upper-dotted line in the plots of trajectories represent the mean of the log transformed arbitrary units (AU) for mothers with confirmed SARS-CoV-2 infection. The lower-dotted lines in the trajectories plot represent the established positive cut-off value (log of the mean+2SD of pre-pandemic anti-SARS-CoV-2 IgA and IgG AU). Mixed-effect analysis with multiple comparisons post hoc test was performed to test the significance in the antibody’s presence in breast milk and the differences according to vaccine type (Additional Table S4). Y-axis marked the approximated days of sampling. C, D Comparison of the increment in log-transformed AU from the determination of SARS-CoV-2 IgG (C) and IgA (D) from baseline to 2 weeks post 1st dose and 30 days after 2nd dose (at the end of the follow-up). 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. 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