Recent advances in DNA vaccine technology has brought about a promising strategy for the control of viruses that contain surface membrane glycoproteins. This type of vaccine involves the intramuscular injection of a bacterial plasmid containing a gene encoding a viral protein. The strategy uses eukaryotic processing of the protein as would naturally occur during a viral infection. In this study, plasmid DNA encoding the glycoproteins of infectious hematopoietic necrosis virus (pcDNA3-IHNV-g), snakehead rhabdovirus (pcDNA3-SHRV-g), or spring viremia of carp virus (pcDNA3-SVCV-g) was injected into the skeletal muscle of rainbow trout fry. At 30 days post-vaccination, fish were challenged with IHNV. Protection against IHNV was observed among all DNA vaccinated groups. Fish injected with plasmid pcDNA3-IHNV-g, pcDNA3-SHRV-g, or pcDNA3-SVCV-g had relative survival rates of 93.2%, 98.3% and 94.9%, respectively. The mechanisms for the viral mediated resistance induced by these glycoprotein based DNA vaccines is unknown. A parallel study conducted by Dr. Carol Kim on the production of Mx proteins in these fish indicates that the observed protection might be a consequence of the stimulation of interferon. / Graduation date: 1999