IFNG and infection: Studies using Norwalk Virus (GI), Snow Mountain Virus (GII) and HuNoV-HS66 (GII) VLPs to evaluate immunity after infection with live virus or immunization with VLPs orally show production of T cell effector cytokines such as IL-2 and interferon γ (IFN-γ) and proliferation of norovirus specific T cells after in vitro restimulation with VLPs [24]–[26].