Comparison of Goose APV Isolate as Vaccine to USDA-Licensed P63 Vaccine
Poultry - 2004
The Problem
Since it was first diagnosed in Minnesota in 1997, the avian pneumovirus (APV)-induced rhinotracheitis has continued to be a major problem affecting 30 to 45 percent of turkey flocks in Minnesota in 2000. The economic losses are estimated at over $15 million per year.
Top
Background
Researchers have determined that the viruses responsible for the outbreaks in the U.S. are genetically and antigenically similar but different from APV isolates from other parts of the world. They have recently isolated an APV strain from Canadian geese, and preliminary studies suggest that this virus is only mildly pathogenic to susceptible turkeys but confers a strong and protective immune response. Using RARF funds provided in 2002, the research team has sequenced goose APV/MN-15a and determined that the vaccine strain shares considerable homology with turkey APV isolates. Turkey farmers and field veterinarians have requested the researchers perform a direct comparison of vaccine potential between this virus and a recently USDA-approved P63 vaccine. Clearly, if this wild bird APV isolate proves safe and more efficacious than P63 it will become a major tool for fighting the APV outbreaks.
Top
Objectives
To date, no direct comparisons of the P63 commercially available vaccine and the goose isolate vaccine strain have been done. The central hypothesis of this project is that goose APV-15a vaccine strain confers better protective immunity in commercial turkeys than the commercially available P63 vaccine. The objective of this project is to directly compare protection, induction of antibodies, and induction of cell-mediated immune response (CMI) between the two vaccines. The recent development of a good CMI assay in Dr. Sharma’s laboratory using a recombinant APV protein generated from Dr. Njenga’s laboratory will enable the researchers to perform unique and highly informative in vitro assays.
Top
Work Plan
1. Directly compare protection conferred by goose APV-15a vaccine and Biommune p63 vaccine using week-old commercial turkey poults.
2. Examine induction of antibodies and cell-mediated immunity by the two vaccines.
3. Compare protection of the two vaccines in day-old commercial turkey poults.
Top
