In a separate set of children’s samples in sub-study (iv) (Fig. 5a, Table 1), including samples pre/post-vaccination, and pre/post-infection, we increased our protein panel to 19 seasonal and avian influenza HA proteins (Supplementary table 1) to determine antibody binding breadth (for IgG, IgG1, IgG3, IgA1, IgM, FcγR3a and FcγR2a binding). This evidence concerns the gene IGHA1 and infection.