Model 1 (Supplementary Fig. 5a) showed that sH3-2007-IgG1 and IgG3, followed by vaxx sH1-2007-FcγR3a, pH1-FcγR3a, H1stem-IgG, pH1-IgG1 and IgG3 as antibody features were significant to predict pH1N1 infection, whilst Model 2 ranked HAI titers to pH1 and sH3-2007-IgG1 first, followed by H1Stem-IgG1 and sH3-2007-IgG3. Here, IGHG3 is linked to infection.