Adjuvants And Delivery Methods: Current And Novel

Vaccination is the most appropriate method to control infectious diseases that threaten the aquaculture industry worldwide. Unfortunately, vaccines are usually not able to confer protection on their own, especially those vaccines based on recombinant antigens or inactivated pathogens. Therefore, the use of adjuvants or immunostimulants is often necessary to increase vaccine efficacy. Furthermore, an important additional problem that limits the entry of novel fish vaccines to the market is that many of the vaccines experimentally produced only work when injected (either intraperitoneally or intramuscularly). Therefore, the search for alternative methods of mass vaccine delivery (oral or immersion) should also be addressed in parallel. Unfortunately, it is probable that the search for a specific combination of antigen/adjuvant/delivery method has to be experimentally addressed for each pathogen/fish species, and only a few general conclusions can be drawn from each of these studies. In this chapter, we summarise previous studies performed with both traditional and new generation adjuvants as well as those studies that have explored methods for vaccine delivery alternative to injection.