Submitted to: American Association of Avian Pathologists
Publication Type: Abstract only
Publication Acceptance Date: 12/30/2009
Publication Date: 8/1/2010
Citation: Susta, L., Miller, P.J., Decanini, E.L., Absalon, A.E., Afonso, C.L., Brown, C.C. 2010. Pathological and immunohistochemical study of the reproductive tracts of vaccinated layers infected with the virulent CA02 strain of Newcastle disease virus [abstract]. In: Proceedings of the American Association of Avian Pathologists annual meeting, July 31-August 04, 2010, Atlanta, Georgia. Paper #9394. Interpretive Summary:
Technical Abstract: To evaluate the relevance of humoral antibodies induced by Newcastle disease vaccine viruses homologous or heterologous to the challenge virus on protection of the reproductive tract, twenty-two week-old commercial layers previously vaccinated four times with live B1 vaccines were boosted with one of two inactivated vaccines and compared to a sham-boosted (normal allantoic fluid) group. Boosts were performed with inactivated antigen obtained from the virulent strain/CA02 or the lentogenic strain/LaSota. Three weeks later, serum was collected for hemagglutination-inhibition (HI) assays and the birds were challenged with the CA02 strain, via eye drop and nasal instillation. Selected chickens were necropsied at various days post-infection, the reproductive tract examined for gross pathology and samples taken for microscopic examination. Microscopic lesions consisted of edema, perivascular lymphoid follicles and plasmacytic infiltration in the lamina propria of the infundibulum in sham-boosted birds starting at day 11. In birds boosted with LaSota or CA02 complete protection from lesions was observed.