Scientists to create fish vaccine pellet

Researchers at Idaho State University have received a grant to develop a food pellet vaccine for hatchery rainbow that, if successful, could lead to new ways to vaccinate livestock and even humans.

"There is no real effective oral delivery system for any vaccine," said Wendy Sealey, a University of Idaho professor at the Aquaculture Research Institute in Hagerman. "If we can get this to work in trout, the real potential is not only for trout and this disease. We could apply this to other species and other diseases."

The state Board of Education recently gave the university a two-year, $550,000 grant to come up with a way to reduce infectious hematopoietic necrosis virus in farm-raised trout.

The disease causes slime to accumulate near a fish's gills and eventually kills the fish by suffocation. Sealey said about 30 percent of farm-raised trout—an industry that generates $40 million to $50 million annually in Idaho—are lost to the disease.

Sophie St. Hilaire, an ISU biology professor and the project's lead researcher, said getting the vaccine from the pellet into the trout's bloodstream is difficult because fish have two stomachs.

"When you feed something to the fish, their gut breaks it down," Hilaire told the Idaho State Journal. "The delivery system will protect (the vaccine) so it can be taken up in the lower gut where nutrients are absorbed."

That will be done by delaying when the pellet breaks down so that the vaccine makes it through the first stomach and into the second, she said.

ISU pharmaceutics professor John Eley is trying to devise a way to make that work.

"We have the idea it will benefit stocked fish and fish farming," Eley said. "Fish farming is our first focus. It could eventually benefit land animals, such as livestock, for other diseases. Humans could also benefit."