ARS | Publication request: Exchange of Newcastle disease virus fusion and hemagglutinin-neuraminidase genes into a vaccine backbone: effects on virulence

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 7, 2011
Publication Date: January 26, 2012
Citation: Cardenas Garcia, S., Susta, L., Diel, D.G., Decanini, E.L., Absalon, A., Brown, C., Yu, Q., Miller, P.J., Afonso, C.L. 2012. Exchange of Newcastle disease virus fusion and hemagglutinin-neuraminidase genes into a vaccine backbone: effects on virulence . Meeting Abstract. 50:378-387.

Technical Abstract: Newcastle Disease Virus (NDV) is the causative agent of Newcastle disease (ND), a very important infection that causes significant economic losses to the poultry industry. Currently, viruses of genotypes V, VI, and VII circulate worldwide causing significant mortality in poorly vaccinated chickens. The most widely used method to control ND is vaccination with the live LaSota vaccine, a class II, genotype II virus. Recombination between the LaSota vaccine virus and virulent viruses of genotype VII has been reported in Asia. However, the effect of those genetic exchanges on virulence has not been evaluated. To assess the potential risks of exchanging virulent genes into vaccine backbones, here we generated LaSota vaccine-based recombinant viruses with the replacement of the fusion (F) and hemagglutinin-neuraminidase (HN) genes from a mesogenic virus representative of genotype VI, and from three velogenic virus representatives of genotypes V, VIIa, and VIId, respectively, using reverse genetics approaches. The pathogenicity of these recombinant viruses was assessed and compared with that of their correspondent wild type viruses. Mean Death Time in eggs (MDT), Intracerebral Pathogenicity Index (ICPI) assay values in day-old chickens, and survival of infected naïve adult birds were analyzed.