Development of an orally administered novel sea lice vaccine targeting mucosal immunity

Sea lice, Lepeophtheirus salmonis, are the major disease constraint to Atlantic salmon aquaculture sustainability. A wide range of treatment and management tools are employed for control, however, increasing parasite resistance to drug treatment is reducing the effectiveness of chemotherapeutic treatments. Development of a sea lice vaccine would represent a major advance in sea lice control, providing a practical, eco-friendly and widely applicable tool for use in the integrated sea lice control strategy.

So far, mostly injection vaccines have been developed and tested and no commercial vaccine currently exists. This project seeks to develop a novel orally delivered efficacious sea lice vaccine, exploiting recent knowledge on salmonid mucosal immunity and sea louse biology, coupled with innovative tools for vaccine development and delivery. The lead industry partner, BioMar, has developed immunomodulatory feeds that improve fish resistance/responsiveness to sea lice, which will complement oral immunisation. Previous collaborations between the lead academic partner, University of Stirling’s Institute of Aquaculture (IoA), project partner Tethys Aquaculture, and subcontracted member, Moredun Research Institute (MRI), led to the discovery of a panel of sea louse vaccine candidates, which will be produced as recombinant protein vaccines in the present study.

IoA’s previous work with project partner Sisaf Ltd demonstrated enhanced mucosal immune responsiveness of salmonids to orally delivered bacterial and viral antigens incorporated into silicon nanoparticles (SiNPs). This collaborative background sets the foundation for this consortium to develop a novel oral sea lice vaccine, using a yeast recombinant protein expression platform for antigen production and SiNPs for oral administration in conjunction with functional immunomodulatory diets to enhance localised effector mucosal immune responses to sea lice. 

The key objectives of this project are to identify (1) an appropriate mucosal vaccination regime; (2) a commercially viable sea louse vaccine antigen production platform and (3) an oral antigen administration vehicle for vaccinating against sea lice. Additionally, a lab-based assay will be developed to determine sea louse vaccine antigen efficacy in vitro.