Location: Endemic Poultry Viral Diseases Research
Project Number: 6040-32000-083-004-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Jul 1, 2020
End Date: Jun 30, 2023
Compare vMDV and vvMDV challenge strains in commercial broiler-type chickens to determine optimal strain for HVT-vectored vaccine protection trials.
Experiment 1: We will evaluate the current vMDV standard strain GA/22, acknowledged by CVB, as well as RB-1B BAC and five vvMDV candidates (Md5, 608, 610B, 568A, and 656A). These isolates were chosen based on isolation of majority of the isolates from broiler-type chickens and/or best protection using HVT vaccines (Witter, 1997). A second replicate following completion of the first replicate will be conducted to confirm results and allow for modifications of challenge strains, if necessary. Each bird line will be genotyped for MHC variation using an MHC-specific SNP panel comprised of 89 SNPs encompassing 210,000bp of the MHC-B region. Experiment 2: Based on results from Experiment 1, 1-2 of the best challenge isolates will be evaluated for vaccine efficacy as well as either challenge route or bird source.