ANIHWA PlantVac: Sustainable management of aquaculture fish health through the development of low cost plant-derived fish vaccines

The aquaculture industry is the fastest growing food-producing sector worldwide. To achieve a sustainable aquaculture food-fish production and manage the aquaculture fish health, vaccination has been found to be an effective method for increasing economic output and improving animal welfare. It has also permitted the development of more sustainable fish farming with reduced use of antibiotics and chemicals. Since viral diseases pose a serious threat to aquacultures worldwide, lack of preventive measures has extensive negative consequences. For instance, pancreas disease (PD), a viral fish disease caused by the Salmonid alphavirus (SAV) has a significant impact on Norwegian salmonid aquaculture as well as in other European countries e.g. UK. Another fish viral disease, viral haemorrhagic septicaemia (VHS), which can affect most species of salmonid fish reared in fresh water or sea water, is caused by the VHS virus. The economic loss caused by VHSV on farmed rainbow trout is a challenging task in Finnish aquaculture. Outbreaks of VHS have also occurred in Norway and the UK. VHSV has been detected in marine fish, and is known to have high mutation rate and adaptability. Thus, there is an urgent need to develop low-cost fish vaccines to assist sustainable aquaculture production in Europe. Cardiomyopathy syndrome (CMS) caused by piscine myocarditis virus (PMCV) infection is an emerging disease of farmed salmon, usually affecting relatively large fish in the marine phase. The virus transmits primarily via water with a risk of spread to wild salmon. PMCV cannot be cultured in available cell culture, which has made vaccine development with whole virus antigen difficult. Recombinant vaccine antigen is therefore an option for improved management of PMCV. The prototype fish vaccine against CMS can be taken to the market eventually by industrial partner(s), if experimental challenge studies shows sufficient efficacy. The PlantVac consortium consisting of four Europeans partners in three countries (Norway with 2 partners, UK and Finland) aims to advance our existing plant-based recombinant protein production technologies to establish a transnational plant-based low cost vaccine production platform to facilitate the future production of fish vaccines in large quantity at low cost. We have selected PD and VHS as two cases for proof-of-principle and will test our three different tobacco-production technologies (i.e. transient expression by producing virus like particles, chloroplast genetic engineering and tobacco BY-2 cell line platform). Moreover CMS was added to the candidate antigen list after VHS target G-protein failed to be expressed in tobacco chloroplasts under workpackage (WP) 3b. Through the 3-year project period, the PlantVac consortium has carried out many activities to fulfil the designed tasks and our main scientific achievements have been presented as 22 publications (including peer-reviewed and popular science publications, as well as conference presentations), in two project progress reports (the interim and final reports) and a dissemination conference: the Biotechnology for Bioeconomy (B4B) conference organised by P1 on August 11, 2016, at NIBIO, Norway, for communicating our project nationally and internationally. This conference attracted 155 participants with excellent invited talks given by Nobel Laureate Sir Richard Roberts, Prof. Ralph Bock, Prof. Caixia Gao, and others. The PlantVac project has demonstrated that plants can be used as one of the promising fish vaccine production platforms for effective management of aquaculture fish health in the future. The candidate fish vaccine antigens produced in the PlantVac project will be investigated further when funding is made available or in collaboration with industrial partners. The knowledge and experience that the PlantVac consortium has acquired are very valuable for the future research. In addition to the scientific achievements made during the project period, another most important achievement is that the PlantVac project provided a platform for the partners with different scientific backgrounds and expertise to work together in order to contribute to the future aquaculture fish health, food safety and environmental protection.

To achieve a sustainable food-fish production and manage the aquaculture fish health, vaccination has been found to be an effective method for increasing economic output and improving animal welfare. It has also permitted the development of more sustainable fish farming with reduced use of antibiotics and chemicals. Since viral diseases pose threat to aquacultures worldwide, this lack of preventive measures has extensive negative consequences. For instance, pancreas disease (PD), a viral fish disease caused by the Salmonid alphavirus (SAV) has a significant impact on Norwegian salmonid aquaculture and in other European countries. Another fish viral disease, viral haemorrhagic septicaemia (VHS), which can affect most species of salmonid fish reared in fresh water or sea water, is caused by the VHS virus. The economic loss caused by VHSV on farmed rainbow trout is a challenging task in Finnish aquaculture. Outbreaks of VHS have also occurred in Norway and the UK. VHSV has been detected in marine fish, and is known to have high mutation rate and adaptability. Thus, there is an urgent need to develop low-cost fish vaccines for sustainable aquaculture production in Europe. Thus, we three Europeans partners (Norway, UK and Finland) aim to advance our existing plant-based recombinant protein production technologies to establish a transnational plant-based low cost vaccine production platform to facilitate the future production of fish vaccines in large quantity at low cost. We have selected PD and VHS as two cases for proof-of-principle and will test our three different tobacco-production technologies (i.e. transient expression by producing virus like particles, chloroplast genetic engineering and tobacco BY-2 cell line platform). The PlantVac consortium consists of experienced scientists with the required expertise on plant production systems, fish health, veterinary immunology and economics. The proposed project is highly relevant for all the participating countries.