Submitted to: American Association of Avian Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: December 17, 2008
Publication Date: May 8, 2009
Citation: Miller, P.J., Afonso, C.L. 2009. Transmission of virulent Newcastle disease virus (NDV) between unvaccinated, sub-optimally vaccinated, and well-vaccinated SPF chickens [abstract]. American Association of Avian Pathologists/American Veterinary Medical Association annual meeting, July 11-15, 2009, Seattle, Washington. Paper #7606. Technical Abstract: The purpose of this study was to determine the transmissibility of virulent Newcastle disease virus (NDV) in vaccinated chickens. Chickens were vaccinated with live LaSota and challenged 21 days later with CA02. Two days after challenge, the vaccinated and infected chickens were moved into clean isolators with naïve or vaccinated contact birds. None of these naïve contact birds underwent seroconversion or shed virus, even though the infected birds were shedding virus. However, if vaccinated birds where challenged with CA02 prior to 21 days (i.e. imperfect 3, 5, and 10 days post vaccination), they were able to transmit virus to naïve and vaccinated contact birds. In experimental conditions, vaccination with live LaSota prevents transmission if a sufficient time is given for an optimal immune response.