Developing vaccine platforms for eliciting systemic and mucosal immunity against an emerging viral disease in rainbow trout

Emerging infectious diseases threaten the production and sustainability of the aquaculture industry.Most of these diseases start at mucosal barriers, and therefore, developing effective strategies that
protect fish mucosae is essential to aquatic disease prevention. Rainbow trout is the most important
species in inland aquaculture in the western hemisphere, due to their rapid growth, tolerance to high
densities and market demands. Rainbow trout trading is substantial in many countries, including in
Israel and the US. Recently, we identified a novel virus from rainbow trout suffering from a hepatic
granulomatotic disease, which we named trout granulomatous virus. This virus infects young and
adult trout gills and produces chronic lesions in the liver of adult fish. We have successfully
sequenced and assembled the complete genome of the trout granulomatous virus and found that it is
a corona-like nidovirus. This proposal aims to understand the disease etiology and immunity to the
trout granulomatous virus in trout and to develop effective mucosal vaccines against this virus.
Vaccine platforms will include: (i) DNA-based vaccines and (ii) virus-like particles. The mucosal
vaccines will leverage our cutting-edge, recent findings in the field of fish mucosal adaptive immune
responses to vaccination. This innovative proposal will be led by an international team of experts
with complementary backgrounds in fish viral diseases, vaccine development, and mucosal
immunity. The outcomes of this proposal will strengthen Israel and US aquaculture research
collaboration and create much-needed preparedness for the trout granulomatous virus as well as for
other emerging diseases in farmed fish.