Advances in vaccines developed for bacterial fish diseases, performance and limits

Abstract

In aquaculture, resolving disease problems with antibiotic-medicated food is a general practice but has led to antibiotic resistance of several pathogens, resulting in a higher dose requirement for effective control; this matter is increasing public concern. Scientists are focusing more to support prophylactic strategy in aquaculture that uses vaccines as a preventive measure. Beneficing of the new technology emerging, three principal forms of vaccines are in advance: inactivated form, live attenuated form and DNA-based vaccine form. Regarding some diseases, fish vaccination was employed successfully to protect the farmed fish from the common pathogens. Some vaccines are licensed and commercially available overall the world, others still in experimental phases. Autogenous vaccines are specifically developed and their uses are restricted to defined sites. The administration routes, the ambient conditions, the heterogeneity of biochemical and serological characteristics of pathogens remain the biggest obstacle in developing an effective commercial vaccine. In this review, we intend to update the advances acquired in the fish vaccine and we discuss the advantages, the limitations, and the challenges encountered in this promising preventive approach in aquaculture.