CD79A and infection: Polyclonal IgG, obtained by fractionation of pooled plasma, has been shown to contain antibodies that are broadly cross-reactive across different influenza A subtypes.12–14 While these cross-reactive antibodies are present at low levels, topical application protected 90% of mice.8 Polyclonal IgA-containing preparations have yet to be compared with IgG obtained from the same pool of plasma donors for the presence of cross-reactive anti-influenza antibodies and their capacity to alter the course of infection after topical application.