Abstract: The present invention relates generally to infectious pancreatic necrosis virus (IPNV) and specifically to further characterisation of the genetic stability of IPNV genome. More in particular, the invention relates to greater appreciation and understanding of the frequency of mutagenesis and codon interactions that influence the replication capabilities, virulence and immunogenicity of the virus. There is provided for the first time a method for developing a commercially applicable IPNV vaccine and a vaccine comprising the IPNV genome carrying particular mutations and codons. There are also described uses in prophylaxis or treatment of infectious pancreatic necrosis (IPN) disease.

Abstract: The present invention relates to a live avirulent infectious pancreatic necrosis virus which has been shown to be genetically stable in biological studies. Fish exposed to said virus turn out positive for the virus without showing any signs of disease and the avirulent virus has also been shown to protect the fish against IPN for an extended period of time after administration. Thus, a vaccine comprising said virus and said virus for the prophylaxis or treatment of infectious pancreatic necrosis disease are also part of the present invention.

Abstract: An aquatic subunit vaccine comprises an antigenic fusion protein and suitable carrier or adjuvant. The antigenic fusion protein sequence consists from its amino terminus to carboxyl terminus of a receptor binding motif and a translocation domain of Pseudomonas aeruginosa exotoxin A and has the amino acid sequence of SEQ ID No: 8; a viral antigenic protein affecting fish disease; and a signal peptide having the amino acid sequence of SEQ ID No: 10.

Abstract: A subunit vaccine for aquaculture comprises an antigen fusion protein, and appropriate carriers or adjuvants. From amino terminal to carboxyl terminal, the antigen fusion protein comprises domain I and domain II of Pseudomonas aeruginosa exotoxin A; a viral antigenic protein producing a fish disease; and a signal peptide of a protein.