Overview of recent DNA vaccine development for fish

Since the first description of DNA vaccines for fish in 1996, numerous studies of genetic immunisation against the rhabdovirus pathogens infectious haematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV) have established their potential as both highly efficacious biologicals and useful basic research tools. Single small doses of rhabdovirus DNA constructs provide extremely strong protection against severe viral challenge under a variety of conditions. DNA vaccines for several other important fish viruses, bacteria, and parasites are under investigation, but they have not yet shown high efficacy. Therefore, current research is focussed on mechanistic studies to understand the basis of protection, and on improvement of the nucleic acid vaccine applications against a wider range of fish pathogens.