Naked DNA vaccination of Atlantic salmon Salmo salar against IHNV

• Published in: Diseases of aquatic organisms 1999-11, Vol.38 (3), p.183-190
• Main Authors: TRAXLER, G. S, ANDERSON, E, LAPATRA, S. E, RICHARD, J, SHEWMAKER, B, KURATH, G
• Format: Article
• Language: English
• Subjects: Animal aquaculture; Animal productions; Animals; Antibodies, Viral - blood; Aquaculture; Biological and medical sciences; Disease Transmission, Infectious - veterinary; DNA vaccines; DNA, Viral - chemistry; Fish Diseases - immunology; Fish Diseases - prevention & control; Fish Diseases - virology; Fresh Water; Fundamental and applied biological sciences. Psychology; Immersion; Immunization, Passive - veterinary; Infectious hematopoietic necrosis virus; Marine; Microbiology; Neutralization Tests - veterinary; Oncorhynchus mykiss - virology; Pisciculture; Plasmids - chemistry; Rhabdoviridae - genetics; Rhabdoviridae - immunology; Rhabdoviridae Infections - immunology; Rhabdoviridae Infections - prevention & control; Rhabdoviridae Infections - veterinary; Salmo salar; Seawater; Vaccination - veterinary; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, DNA - immunology; Vaccines, DNA - standards; Vertebrate aquaculture; Viral Vaccines - immunology; Viral Vaccines - standards; Virology
• ISSN: 0177-5103; 1616-1580
• DOI: 10.3354/dao038183

A naked plasmid DNA encoding the glycoprotein (pCMV4-G) of a 1976 isolate of infectious hematopoietic necrosis virus (IHNV) obtained from steelhead Oncorhynchus mykiss was used to vaccinate Atlantic salmon Salmo salar against IHNV. Eight weeks post-vaccination the fish were challenged with a strain of IHNV originally isolated from farmed Atlantic salmon undergoing an epizootic. Fish injected with the glycoprotein-encoding plasmid were significantly (p < 0.05) protected against IHNV by both immersion and cohabitation challenge. Survivors of the first challenges were pooled and re-challenged by immersion 12 wk after the initial challenge. Significant (p < 0.05) protection was observed in all of the previously challenged groups including those receiving the complete vaccine. Fish injected with the glycoprotein-encoding plasmid produced low levels of virus-neutralizing antibodies prior to the first challenge. Neutralizing antibodies increased in all groups after exposure to the IHNV. Passive transfer of pooled sera from pCMV4-G vaccinates and IHN survivors provided relative survivals of 40 to 100% compared to fish injected with sera collected from fish immunized with control vaccines or left unhandled. In this study, DNA vaccination effectively protected Atlantic salmon smolts against challenges with IHNV.