DNA is as effective as protein at inducing antibody in fish.

Antiviral vaccines are needed for fish. 50 microg plasmid DNA in saline by the intramuscular route and 10 microg beta-gal protein in a commercial oil adjuvant by the peritoneal route induced serum antibody of the same titre and avidity in goldfish. The DNA expressed beta-gal under control of the immediate early promoter/enhancer gene of human cytomegalovirus. Commercial bacterin vaccines are administered to fish by the intraperitoneal route with oil and this route for DNA induced only 2-fold less antibody than DNA by the intramuscular route. Bacterin vaccines and antiviral plasmid DNA could therefore be co-injected into the peritoneum of fish in an oil adjuvant as a single dose.