Submitted to: Popular Publication
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/1/2006
Publication Date: 2/1/2006
Citation: Klesius, P.H., Evans, J.J., Shoemaker, C.A. 2006. Advancements in fish vaccine development. Aquaculture Health International. Issue 4 February 2006 page 20-21. Interpretive Summary: In recent years, notable advancement in fish vaccines and delivery methods has been accomplished. Examples of the advancements are the use of extracellular products in killed streptococcal vaccines that are highly efficacious in tilapia. The development and commercialization of attenuated vaccines against Edwardsiella ictaluri (ESC) and Flavobacterium columnare (columnaris disease) in catfish were also significant advancements. Vaccination of fish using pathogen antigen-encoded DNA is an example of another advancement that has been reported, especially effective against some fish viral diseases. In ovo and oral delivery systems are notable advancements in methods for mass immunization of fish. Increased global trade of aquaculture products and decreased negative impact of diseases are dependent on the continued advancement of fish vaccines and delivery systems.
Technical Abstract: Prevention of fish diseases has become more dependent on the use of vaccines. Efficacious modified-killed Streptococcus iniae and Streptocococcus agalactiae vaccines were developed and patented by the USDA, Agricultural Research Service (ARS), Aquatic Animal Health Laboratory (AAHL). These vaccines confer protection for 180 days or longer post-vaccination. This protection was correlated with specific antibody responses against these pathogens. The finding that extracellular products of Gram-negative streptococci are important immunogens that confer protective immunity following immunization is a notable advancement in the development of efficacious vaccines. Another biotechnical breakthrough was the USDA, ARS, AAHRL development of and U.S- licensing of the first attenuated bacterial vaccines against Edwardsiella ictaluri (ESC) and Flavobacterium columnare (columaris disease). These diseases cost the catfish industry about $90-100 million, annually. Both of these vaccines were licensed to Intervet, Inc., Millsboro, DE, which commercialized the vaccines. The benefit of the ESC vaccine is an increase of producer profit by $1,706 per acre. Other examples of advancements in fish vaccines are mass vaccination methods. Immunization of eyed catfish eggs (in ovo vaccination) was successfully achieved using the attenuated ESC vaccine. PerOs System Technologies, ST Nicolas, Canada development a patented OraljectTM technology which provides for oral immunization by preventing the degradation of the vaccine’s components. The ARS S. iniae vaccine was successful incorporated into the OraljectTM technology and shown to be efficacious in tilapia. Vaccines are part of a management tool that are being used to limit the serious economic losses caused by disease.