In contrast, the European Society for Immunodeficiencies (ESID) [10] criteria emphasize the (i) presence of low IgA, (ii) usage of low switched memory B cells, instead of measurement of antibody response to vaccine, (iii) exclusion of profound T-cell deficiency, and (iv) a clinical manifestation of disease such as an increased susceptibility to infection, autoimmune manifestations, granulomatous disease, or unexplained polyclonal lymphoproliferation, or an affected family member with antibody deficiency. This evidence concerns the gene CD79A and infection.