Subunit immersion vaccines for fish

1. A vaccine for fish comprising an antigenic fusion protein, wherein the antigenic fusion protein has a leader sequence consisting of the amino acid sequence of residues 1-90 of SEQ ID NO:7, and an antigenic fragment comprising an amino acid sequence of a histone like protein (HLP) from Tenacibaculum maritimum ( T. maritimum ), Flavobacterium columnare ( F. columnare ) or Flavobacterium psychrophilum ( F. psychrophilum );

wherein the amino acid sequence of the HLP from T maritimum has the amino acid sequence of SEQ ID NO:2, wherein the amino acid sequence of the HLP from F. columnare has the amino acid sequence of SEQ ID NO:4, and wherein the amino acid sequence of the HLP from F. psychrophilum has the amino acid sequence of SEQ ID NO:6.

2. The vaccine of claim 1 , wherein the antigenic fusion protein comprises an immunostimulatory fragment consisting of the amino acid sequence of residues 97-111 of SEQ ID NO:7.

3. The vaccine of claim 1 , wherein the vaccine further comprises at least a second different isolated antigen.

4. The vaccine of claim 3 , wherein the second isolated antigen is an infectious pancreatic necrosis virus (IPNV) antigen.

5. The vaccine of claim 1 , further comprising at least one additional agent selected from the group consisting of Aeromonas hydrophilia, Aeromonas salmonicida, Pseudomonas fluorescens, Vibrio anguillarum, Vibrio salmonicida, Renibacterium salmoninarum , infectious haemopoietic necrosis virus (IHNV), infectious salmon anemia virus (ISAV), pancreas disease virus (PDV), salmon alphavirus (SAV), salmon poxvirus, and viral haemorrhagic septicemia virus (VHSV).

6. A method of immunizing a fish comprising administering to said fish an immunologically effective amount of the vaccine of any one of claims 1 , 2 , and 3 - 5 , wherein the method immunizes the fish against F. columnare, F. psychrophilum , or T. maritimum.