By Sarah Brown

 New vaccine technology will provide producers with more effective and efficient vaccination methods, says a Saskatchewan researcher.

Dr. Philip Griebel, Pathogenomics Project Head for the Vaccine and Infectious Disease Organization in Saskatchewan, is working towards developing mass-market oral vaccines for livestock such as beef cattle and sheep. That could mean vaccinating livestock will be less burdensome for producers.

These edible vaccines will address meat quality issues by replacing needle vaccinations, and will ensure direct delivery and effective immune response development where it’s needed.

“Producers will benefit substantially,” says Griebel. “The vaccine cost will be comparable but all indirect costs such as time, labour and infrastructure can be eliminated – and that provides considerable savings for producers.”

Researchers have successfully identified and tested the vaccine delivery system in both sheep and cattle. The system is composed of a bovine adenovirus component (which helps to initiate and enhance immune responses in the animal) encased in something called an alginate microsphere (a protective protein globule derived from algae) that allows the virus vaccine to pass through the four ruminant stomachs to the small intestine, where it can be taken up into the blood. That protects the virus from degrading in stomach fluids.

This delivery system can act as a vehicle to transport a number of different vaccines to ruminant animals. Producers, says Griebel, will be able to orally vaccinate their livestock at optimal times for problems such as intestinal diseases or respiratory infections.

“This technology will enable vaccine delivery at the highest period of disease risk rather than at a time of convenience, which will greatly enhance its effectiveness,” he says.

Griebel’s work mirrors some oral vaccine research that’s taking place in Ontario . At the University of Guelph , Prof. Patricia Shewen, Department of Pathobiology is part of a team that’s working on its own edible vaccine, by create a genetically altered plant that can vaccinate the animals that eat it.

“The ideal approach in vaccination is to introduce the organism that causes disease through its natural route of entry into the body,” says Shewen. At present she’s using alfalfa as the basis for a shipping fever vaccine.

The next step for Griebel and his research team is to determine a production method that will enable identical replication of the delivery components. While the delivery system works on a test scale, the researchers need it to be stable enough for consistent large-scale production to ensure adequate quantities are available on the market.

Perfecting the delivery system and manufacturing processes for this oral vaccine will take about 10 more years, says Griebel. But he’s optimistic that livestock will soon be able to eat their way to a healthier existence.

Research funding is provided by Alberta Beef Producers, the Natural Sciences and Engineering Research Council, the Ontario Cattlemen’s Association and the Western Canadian Adaptation and Rural Development Fund.