In the absence of a cell culture system for HuNV, virus like particles (VLPs) that assemble when the viral capsid protein is expressed have been important for evaluating norovirus immune responses [20] [21] [22] [23] . 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 c (IFN-c) and proliferation of norovirus specific T cells after in vitro restimulation with VLPs [24] [25] [26] . These studies show that T cell responses develop, but do not define their role in either clearance of primary infection or resistance to re-challenge.