In another report exploring pre-infection cellular components related with asymptomatic and symptomatic influenza illness in vaccinated and unvaccinated adult individuals, it has been revealed that protection from infection is associated with increased frequency of polyfunctional CD4+ and CD8+ T cells, circulating T follicular helper, myeloid dendritic cells, Th17 cells and innate effector CD16-expressing cytotoxic and cytokine-producing NK cells100. This evidence concerns the gene CD4 and infection.