Project Number: 6612-32000-049-00
Project Type: Appropriated

Start Date: Nov 15, 2006
End Date: Nov 14, 2011

Objective:
1. Identify determinants of virulence, tissue tropism and host range of avian paramyxoviruses. 2. Development of improved Newcastle disease control strategies addressing issues important to virus transmission, vaccines and vaccination, diagnostics, or international trade. Develop models to show vaccination is a viable method of controlling avian paramyxovirus outbreaks. 3. Biological and molecular characterization of emergent or previously uncharacterized Newcastle disease virus (NDV) isolates as the basis for extending the capabilities for epidemiology and the understanding of NDV ecology and evolution.

Approach:
Reverse genetics technology will be utilized to generate viruses with different Newcastle disease virus (NDV) gene mutations or combinations. A comparison of the pathogenesis of those recombinant viruses and their parent viruses in chickens and other bird species will be done to extend the understanding of the role of those genetic changes on tissue tropism and the manifestations of clinical disease of NDV strains that are of a single serotype but vary in virulence. Development of improved Newcastle disease (ND) vaccine formulations will be based on data obtained from the comparative antigenicity of NDV strains of different virus lineages and resultant protection induced to challenge with isolates from recent ND outbreaks. Whole virus vaccine formulations will be compared to recombinant viruses prepared by reverse genetics or vector systems to express optimal antigenic configurations. Development of improved rapid diagnostics with monoclonal antibodies and real-time RT-PCR will be used to improve NDV detection and differentiation capabilities. Expansion of the NDV database of genomic and biological characteristics of recent isolates from poultry and surveillance of wild bird populations will improve our predictive and forensic molecular epidemiology capabilities and provide direction for reverse genetics constructs in studies of pathogenesis and vaccine and rapid diagnostic development.