Smarter Application Improves Catfish Vaccine

New vaccination processes could improve the efficiency and effectiveness of catfish vaccines, according to a study by Agricultural Research Service (ARS) scientists in the agency's Aquatic Animal Health Research Unit, Auburn, Ala.

Diseases like enteric septicemia and columnaris cost the U.S. catfish industry an estimated $50-70 million per year.

ARS molecular biologist Craig Shoemaker, microbiologist Phillip Klesius and aquatic pathologist Joyce Evans invented two vaccines to immunize catfish against these diseases. The vaccines were patented and licensed to international vaccine manufacturer Intervet for distribution.

The team received technology transfer awards from both ARS and the Federal Laboratory Consortium for their efforts. Now, new research is showing how the vaccines should be administered for maximum influence.

Both vaccines can be given to channel catfish eggs about 24-48 hours before hatching, a recent study found. This suggests they can be successfully vaccinated during the "eyed-egg stage," when they are still in the hatchery—long before they're exposed to pond pathogens. Currently, fish are vaccinated when they are 10 days old, in the trucks that transport them to the ponds where they will be raised.

The study also proved that the two vaccines could be administered simultaneously, making the treatment more efficient. This is beneficial, as both pathogens frequently appear in the same ponds.

The 10- to-15 minute process is easy, safe and effective. The catfish are still protected against the disease 140 days after immunization.

Effective vaccines have multiple benefits, the most important of which is improved fish health. Vaccinated fish also require fewer chemicals and antibiotics to fight disease. And they grow faster than nonvaccinated fish, which translates to higher profits for farmers. One study estimates that fish farmers can increase their profits by about $2,000 per acre using vaccines like these.

ARS is the U.S. Department of Agriculture's chief scientific research agency.