Submitted to: Avian Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/17/2002
Publication Date: 11/15/2002
Citation: Kapczynski, D.R., Perkins, L., Sellers, H.S. 2002. Intranasal vaccination with inactivated avian metapneumovirus vaccine induces antibodies with decreased neutralization capability following virus challenge in turkeys. Avian Diseases. Interpretive Summary: Avian metapneumovirus (aMPV) is the cause of a respiratory disease in turkeys. Since there are no treatments available for aMPV infection, efforts to prevent the disease in the U.S. have focused on flock management practices, controlled exposure to field virus and vaccine development. The objectives of this study were to determine if vaccination with inactivated aMPV given in respiratory tract protects turkeys from aMPV challenge. The results indicate vaccination with inactivated aMPV does not increase protection from viral infection and can increase histopathologic lesion severity following virus infection.
Technical Abstract: In an effort to examine mucosal immunity, studies were performed to determine if intranasal vaccination with BPL-inactivated avian metapneumovirus (aMPV) subtype C protected turkey poults from clinical disease and virus replication. Although decreases in clinical disease were observed in vaccinated groups, the vaccine failed to inhibit virus replication in the trachea in 97 % of vaccinated birds and positive identification of aMPV from lung tissue was only reported from vaccinated groups. Histopathologically, enhancement of pulmonary lesions following virus challenge was associated with birds receiving the inactivated aMPV vaccine compared to unvaccinated birds. As determined by an enzyme-linked immunosorbent assay (ELISA), all virus challenged groups increased serum immunoglobulin (Ig) G and IgA antibody production against the virus following challenge, however, the unvaccinated group displayed the highest increases in virus neutralizing antibody. On the basis of these results it is concluded that intranasal vaccination with inactivated aMPV does not induce protective immunity and can result in increased severity of histopathologic lesions.