October 29, 2007

US scientists aim to create vaccine pellet for trout disease

Researchers at Idaho State University have received a US$550,000 grant from the state Board of Education to develop a food pellet vaccine for hatchery rainbow trout.

The vaccine would aim to reduce the infectious hematopoietic necrosis virus in farm-raised trout. The disease causes slime to accumulate near a fish's gills and kills the fish by suffocation. About 30 percent of farm-raised trout are lost to the disease each year.

There is currently no effective oral delivery system for vaccines, said Wendy Sealey, a University of Idaho professor at the Aquaculture Research Institute in Hagerman.

If successful, this could lead to new ways to vaccinate livestock and even humans, she said.

Sophie St. Hilaire, an ISU biology professor and the project's lead researcher, said getting the vaccine into the trout's bloodstream is difficult as the fish would break down the vaccine in the upper gut before it can be absorbed in the lower gut.

The researchers intend to delay the pellet break down so the vaccine would be able to reach the second stomach intact.