Anti‐neuraminidase antibodies measured using neuraminidase inhibition assays (NAI) have been shown to be stronger predictors of disease outcome and severity than HAI in several studies [29, 30, 31], nasal IgA can protect against influenza infection [32], and T‐cell immunity has also been shown to be important in protection against shedding and infection outcome of influenza [33, 34]. This evidence concerns the gene CD79A and influenza.