CD79A and influenza: By the end of the first year, infant #1 maintained 6-month IgG antibody levels, which is likely due to new, natural exposure.Supplementary Figure 2 shows the heatmaps of IgG and IgA antibodies to influenza strains measured by multiplex array in paired mother’s serum (MS), breast milk (BM) and infant serum (IS) samples.Figure 2A shows the trajectory of IgG antibodies to selected individual strains.