We next determined whether protection conferred by MNV1.CW3 or MNV ORF2 VRPs was long lived. WT mice were primed and boosted as shown in Figure 2A with MNV1.CW3 or MNV ORF2 VRPs. Mice were then challenged with MNV1.CW3 two, four, 14, or 24 weeks later and MNV titers measured three days post-challenge. Two weeks post-boost, we observed complete protection against ileal MNV1.CW3 infection after vaccination with either MNV1.CW3 (p = 0.0001) or ORF2 VRPs (p,0.0001) compared to reovirus or HA VRP controls ( Figure 2B ). At two weeks, while vaccination with either MNV1.CW3 or ORF2 VRPs limited MNV1.CW3 replication in MLN, live virus vaccination was more effective (p,0.0001) ( Figure 2C ). Live virus vaccination conferred full protection against MNV1.CW3 replication in both the distal ileum and the MLN at four, 14 and 24 weeks after vaccine boost. Vaccination with ORF2 VRPs was also protective, albeit less effective than vaccination with MNV1.CW3 ( Figure 2B and 2C). Thus both live virus and subunit vaccine induce long-term protection against MNV infection, with live virus vaccination providing more complete protection.