[摘要] ABSTRACT: 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 salaragainst 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 previouslychallenged 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 groupsafter 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. Inthis study, DNA vaccination effectively protected Atlantic salmon smolts against challenges with IHNV.
