In this paper we define the mechanisms of immunity to norovirus infection as measured by both vaccination against, and clearance of, mucosal infection. We found that it is possible to generate highly effective, and remarkably long lasting, immunity to norovirus infection by oral exposure to live virus. Further, systemic exposure to the viral capsid protein expressed in a vaccine vector resulted in effective immunity, albeit not as effective as that observed after live virus vaccination. Importantly, this shows that the MNV VP1 protein contains relevant B cell, CD4 T cell and CD8 T cell epitopes. Vaccination was effective in aged mice. Additionally, vaccination in adult mice required the concerted action of CD4 T cells, CD8 T cell, and B cells to be completely protective in the tissues surveyed. Interestingly, the activities of different components of the adaptive immune system in clearance and vaccination were tissue specific, with different cells playing roles in the intestine itself compared to the draining lymph nodes. Perforin was an important effector molecule. These data have important implications for understanding adaptive immunity to an animal norovirus, representative of a genus that causes significant disease in humans.