Mucosal Vaccination with Formalin-Inactivated Avian Metapneumovirus Subtype C Does Not Protect Turkeys Following Intranasal Challenge

Studies were performed to determine if mucosal vaccination with inactivated avian metapneumovirus (aMPV) subtype C protected turkey poults from clinical disease and virus replication following mucosal challenge. Decreases in clinical disease were not observed in vaccinated groups, and the vaccine failed to inhibit virus replication in the tracheas of 96% of vaccinated birds. Histopathologically, enhancement of pulmonary lesions following virus...