Submitted to: Western Poultry Disease Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/10/2004
Publication Date: 3/8/2004
Citation: Kapczynski, D.R., King, D.J. 2004. Vaccine Protection In Chickens And Turkeys Against The 2002 Exotic Newcastle Disease Virus. Western Poultry Disease Conference p.64-65, 2004.
Interpretive Summary: Not required.
Technical Abstract: The objectives of the present study were to extend the knowledge of protection against U.S. exotic Newcastle disease (END) virus by live and inactivated Newcastle disease virus (NDV) B1 vaccines and determine immunity of commercial birds following lethal challenge with a California 2002 (CA02) END virus isolate. Initial experimentation was designed to assess protection of SPF chickens receiving a single dose of a commercially available inactivated or live NDV B1 vaccine from CA02 challenge, as well as different doses of live vaccine followed by challenge. In a subsequent experiment, birds from commercial field operations (broiler-breeders and broilers) in Georgia undergoing routine NDV vaccination programs were challenged with CA02. The results indicate both live and inactivated vaccines protected SPF chickens from lethal CA02 challenge. However, the vaccines were unable to prevent virus shed, determined by virus isolation from oral and cloacal swabs. Results from commercial broiler-breeders indicate resistance to challenge and very few birds shed CA02 virus. In contrast, results following challenge of commercial broilers indicate seventy-five percent of these birds succumbed to challenge, in spite of receiving two live virus vaccinations in the field at 1 and 17 days-of-age. Preliminary studies in turkeys indicated that 21-day-of-age SPF birds were susceptible to END challenge, whilst 40-day-of-age NDV-antibody-negative commercial turkeys appeared resistant to END challenge and did not exhibit overt disease. For vaccine-challenge studies, the presence of maternal antibody in 10-day-of-age commercial birds at vaccination made protective immunity difficult to assess following challenge at 24-days-of-age. A positive correlation was observed between pre-challenge antibody titers and protection. These results demonstrate that NDV vaccines protect against lethal challenge, and the timing of vaccination for commercial birds should be evaluated in END outbreak situations.