Optimisation of novel mucosal vaccines to prevent bacterial diseases of Tilapia (Oreochromis niloticus)

Dr Rowena Hoare, Senior Research Fellow
Institute of Aquaculture, University of Stirling (UK)
Rowena Hoare

Professor Alexandra Adams, Institute of Aquaculture, University of Stirling (UK)
Dr Khalid Shahin, Institute of Aquaculture, University of Stirling (UK)
Dr Matthijs Metselaar, Benchmark Animal Health (UK)
Dr Kim Thompson, Moredun Research Institute (UK)
Dr Thao Ngo, Biotechnology Center of Ho Chi Minh City (Vietnam)

The majority of fish vaccines are multivalent oil-adjuvanted and given by injection. While they provide good protection against bacterial and viral pathogens, they have some drawbacks such as side effects and can only be delivered by injection. Mucosal vaccination of fish- by immersion and oral (in-feed) routes- has many benefits over injection: cost of application, mass vaccination of juveniles, less handling stress leads to less side effects and infections. At present, a limited number of mucosal vaccines are available for fish, primarily due to them being less effective than injection vaccines with shorter duration of immunity. The benefits of application of vaccine to fish by immersion or oral routes are numerous; ease of application being the foremost especially in less developed countries where expensive vaccination machines are not feasible for farmers. Many fish farmers in LMIC countries would benefit from immersion and oral vaccines that can protect their stocks for the duration of production. Development and optimisation of mucosal vaccines is essential to provide protection of aquaculture species worldwide and contribute to reducing the use of antibiotics and thereby antibiotic resistance. This project will modify an existing monovalent vaccine for a bacterial disease of tilapia, Francisella noatunensis subsp. orientalis (Fno), as a proof of concept to demonstrate the benefits of mucosal vaccination. The technology has the potential to be expanded to encompass other bacterial pathogens of fish in future polyvalent vaccines. Training and dissemination of the resulting technology to LMIC’s will be through a workshop in Vietnam.