Immunization with viral antigens: viral haemorrhagic septicaemia.

Viral haemorrhagic septicaemia virus (VHSV), is an enveloped negative strand RNA virus belonging to the rhabdovirus family. Outbreaks of VHS in farmed rainbow trout often lead to very high mortalities and considerable resources are used on disease surveillance and trade regulations in Europe to reduce spread of the disease. An efficient vaccine would be particular useful in the early stage of eradication programmes, as well as in endemic infected areas. Traditional vaccines such as killed or attenuated virus have been under development for the past 20 years, and although experimental protective properties have been demonstrated, no such products have yet fulfilled the requirements for field use. In recent years, considerable efforts have been put into development of a recombinant subunit vaccine. Focus has been put on the envelope glycoprotein (G-protein), which has been shown to be the target of neutralizing and protective antibodies. Several expression systems have been tried, but so far no products have proved superior to the traditional vaccine forms. This paper reviews the work related to VHS vaccine development.