Development of an Ultrasound-Mediated Delivery System for the Mass Immunization of Fish

Losses due to disease in world aquaculture are estimated to be in the billions of dollars annually. Vaccination is effective in preventing disease for many fish pathogens, however, lack of cost-effective methods for delivering vaccines prevents vaccination from becoming more prevalent in aquaculture. We have shown how ultrasound can enhance the uptake of both dissolved compounds and particles from the aquatic medium into fish, non-invasively. Many vaccines that are efficacious by injection do not provide protection when delivered by immersion, however, an ultrasound mediated delivery system could eliminate the need for injection. DNA vaccines have been shown to be very effective in salmon and trout and are a promising alternative to traditional antigen-based vaccines but require intramuscular injection. What we are proposing is to develop an ultrasound-mediated delivery protocol that would enable the mass administration of a vaccine making the process considerably cost-effective, as well as less stressful to the fish. The model for development of this system would be a DNA vaccine attached to biopolymer nanoparticles which we have shown can be used to successfully deliver DNA, including DNA vaccines. The efficacy of the delivery system for rainbow trout will be evaluated by determining gene expression, elicitation of a humoral immune response, and protection from lethal virus challenge.