Submitted to: Aquaculture Miscellaneous Publications
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/2008
Publication Date: 12/1/2008
Citation: Klesius, P.H., Shoemaker, C.A., Evans, J.J. 2008. Vaccines for Warmwater Aquaculture[abstract]. BIT's World Congress of Vaccine 2008.
Technical Abstract: Enteric septicemia and columnaris are two of the major diseases of farm raised catfish. The causative bacteria, Edwardsiella ictaluri and Flavobacterium columnare, respectively, are ubiquitous pathogens that infect all sizes of catfish. No effective control measures were available prior to the introduction of the USDA-ARS licensed vaccines. Previous studies suggested that killed vaccines against both E. ictaluri and F. columnare were not effective when administered by bath immersion. The lipopolysaccharide, a virulence factor of Gram-negative bacteria was modified to produce avirulent vaccine mutants. The modified bacteria were still able to gain entry into the fish for a proper immune response to develop but could no longer cause disease. The modified live vaccines are administered, by bath immersion, a non-stressful and inexpensive process, to large numbers of young fish and provide life long protection. The U.S. government licensed the vaccines by the Technology Transfer Act. The licensed enteric septicemia vaccine (AQUAVAC-ESCTM) was first introduced in 2001. The economic benefit to producers from use of this vaccine alone is approximately $2,000 per acre, due to faster growing catfish that yield greater lengths over non-vaccinated catfish. Also, the vaccine significantly reduces ESC mortality. The licensed columnaris vaccine (AQUAVAC-COLTM), the first efficacious vaccine against columnaris disease in the world, was launched in 2006. These vaccines provide fish farmers with a cost effective means for preventing the two most economically serious diseases in commercial pond-raised catfish. Use of these vaccines significantly reduces the need for antibiotics; thus, decreasing environmental contamination and providing a safe fish product to consumers.