Current Status and Recent Advancements with Immunostimulants in Aquaculture

Immunostimulants are one of the important strategies to eradicate disease outbreaks in aquaculture. Immunostimulants are a substance that can increase the nonspecific immune mechanisms of the target host when administered individually and specific immune responses when administered in combination with an antigen. A variety of materials ranging from selenium atoms to crude microbial components and plant extracts are known as immunostimulants. Immunostimulants remain a hot research topic in the field of aquaculture with thousands of research papers being published every year. In most of the publications, immunostimulants were shown not only to increase the nonspecific immune mechanisms but also reduce the morbidity and mortality of the host upon experimental infection with pathogen. However, this research success is not getting translated into products such as a ‘commercial immunostimulant feed’. This chapter provides the status of recent advancements in immunostimulant research across the world. For brevity, this chapter is divided into various geographical sections and the status and advancement in each section is listed. Finally, we conclude that more efforts from policy makers are required to convert the research output to marketable products.