In our study, both NA2 VLP and commercial swine IAV elicited adequate, although with not significant differences between these groups, levels of IFN-γ secreting T cells after heterologous virus stimulation, in PBMCs collected at 2 weeks after boost vaccination, suggesting a competent Th1 response following infection with the heterologous A/SW/NC/KH1552516/2016 challenge virus. This evidence concerns the gene IFNG and infection.