Skip to main content
ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #335644
Title: Experimental evaluation of killed and live Newcastle disease virus vaccines heterologous to the virulent genotype XII challenge strain from the Peru/2008 outbreak

Author
item Miller, Patti
item CARDENAS-GARCIA, STIVALIS - University Of Georgia
item GORAICHUK, IRYNA - Consultant
item Taylor, Tonya
item DIMITROV, KIRIL - Consultant
item TOSCANO CONTRERAS, ARNULFO - Applied Research(INVESTIGACION APLICADA)
item MADRIGAL SANCHES, VICTOR - Applied Research(INVESTIGACION APLICADA)
item Afonso, Claudio

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary: While all Newcastle disease viruses (NDV) are contained within one serotype and different NDV provide cross-protection against others, antigenically matched strains have been shown to decrease viral shedding. Therefore, using recombinant technology, some companies have directed efforts in developing genotype specific Newcastle disease vaccines targeting the virulent NDV circulating in specific locations. Recombinant NDV vaccines matching genotypes V, VII and XIII have been developed. The goal of this experiment was to evaluate the immunity induced by genotype V, VII, and XIII NDV vaccines in both live and killed formulations and to determine their efficacy after challenge with a genotype XII virulent NDV. Genotype XII NDV have caused outbreaks in Peru and China during the last decade and no homologous vaccines have been developed for these viruses. Other virulent challenge viruses from genotypes V, VII and XIII, homologous to the genotypes of the vaccines, were also used as controls. Hemagglutination inhibition (HI) antibody titers before and after challenge, morbidity rates, mortality rates, number of birds shedding virulent challenge virus, and the relative amounts of shed challenge virus were obtained. All killed vaccines provided 100 % protection with no morbidity or mortality after challenge with the genotype XII Peru virus. The birds vaccinated with killed genotype V and XIII had similar pre- and post-challenge HI antibody titers when tested against the Peru challenge strain antigen. All vaccines provided at least a two log decrease in the amount of challenge virus shed. For the live vaccines, both genotypes V and XIII equally provided acceptable protection with both resulting in 10% morbidity and mortality after challenge. Both vaccines also had similar pre- and post-challenge HI antibody levels, similar numbers of birds shedding virus, and similar amounts of virulent NDV shed (around 2.5 logs less than the unvaccinated controls). To conclude, under these experimental conditions against the virulent Peru challenge virus all of the inactivated vaccines, and the live genotype XIII and V vaccine strains performed equally well in spite of being heterologous to the challenge virus.

Technical Abstract: While all Newcastle disease viruses (NDV) are contained within one serotype and different NDV provide cross-protection against others, antigenically matched strains have been shown to decrease viral shedding. Therefore, using recombinant technology, some companies have directed efforts in developing genotype specific Newcastle disease vaccines targeting the virulent NDV circulating in specific locations. Recombinant NDV vaccines matching genotypes V, VII and XIII have been developed. The goal of this experiment was to evaluate the immunity induced by genotype V, VII, and XIII NDV vaccines in both live and killed formulations and to determine their efficacy after challenge with a genotype XII virulent NDV. Genotype XII NDV have caused outbreaks in Peru and China during the last decade and no homologous vaccines have been developed for these viruses. Other virulent challenge viruses from genotypes V, VII and XIII, homologous to the genotypes of the vaccines, were also used as controls. Hemagglutination inhibition (HI) antibody titers before and after challenge, morbidity rates, mortality rates, number of birds shedding virulent challenge virus, and the relative amounts of shed challenge virus were obtained. All killed vaccines provided 100 % protection with no morbidity or mortality after challenge with the genotype XII Peru virus. The birds vaccinated with killed genotype V and XIII had similar pre- and post-challenge HI antibody titers when tested against the Peru challenge strain antigen. All vaccines provided at least a two log decrease in the amount of challenge virus shed. For the live vaccines, both genotypes V and XIII equally provided acceptable protection with both resulting in 10% morbidity and mortality after challenge. Both vaccines also had similar pre- and post-challenge HI antibody levels, similar numbers of birds shedding virus, and similar amounts of virulent NDV shed (around 2.5 logs less than the unvaccinated controls). To conclude, under these experimental conditions against the virulent Peru challenge virus all of the inactivated vaccines, and the live genotype XIII and V vaccine strains performed equally well in spite of being heterologous to the challenge virus.