mRNA vaccine technology received great concern in worldwide after COVID-2019 pandemic due to high efficacy, quick manufacturing process, safe (non-infectious and non-integration), and cost effectiveness. Since then significant amount of pre-clinical and clinical data have been reported in the mRNA vaccine industry, emphasizing the potential of mRNA vaccines to control various diseases in humans and other animals. In Korea, around 30 fish vaccines have introduced commercially for different pathogens; however, most of them are inactivated vaccines. Moreover, there is no commercialized mRNA vaccines have been developed for the fish until now.
Though the stability and storage are main limitations for the mRNA vaccine preparation, concerning with their advantages we believe mRNA vaccines strategy especially the development for bacteria mRNA vaccines may new step towards to improve the health and productivity of aquatic animals specially the farmed fish. However, selecting a suitable antigen , which elicit humoral and cellular responses, biocompatibility , efficient delivery and cellular uptake, would be crucial for bacterial mRNA vaccine preparation and may be challenging.
Edwardsiella piscicida (Gram- negative bacteria) is an important multi-drug resistant fish pathogen , which causes the disease Edwardsiellosis to broader hosts range . Various virulence factors, such as secretion systems, toxins, and adhesion molecules assist to cause the disease by invading and damage host tissues. The high mortality due to infected fish greatly impacts to economy of the aquaculture industry, thus control and mitigation strategies needs to develop continuously. We proposed that the mRNA vaccine encoding E . piscicida antigen/s that encapsulated with lipid nanoparticles would give great platform for controlling fast spreading of bacteria in fish especially to protect olive flounder (Paralicthys olivaceus ) from the Edwardsiellosis. If the proposed study is succeed, it will be a great contribution to the advancement of the fish field in the future in response to new pathogenic MDR bacterial pandemics.