Infectious diseases have a significant impact on the sustainability of the aquaculture industry, that being in finfish or shellfish/shrimp production environments. The subsequent use of antibiotics, drugs, and chemical disinfectants cause concern at all l evels. The succesful vaccines for salmon farming was developed with an element of trial and error and attempts to extend the experience to other fish species and pathogens have not been similarly successful. This shows there is need for improved understan ding of functional and molecular aspects of fish immune mechanisms. This includes not only development of efficacious vaccines, but also the use molecular tools for monitoring the status of the immune system. Immunoprophylaxis in shrimp farming poses spec ific challenge since invertebrates cannot be vaccinated by traditional means. Recent findings indicate however that priming of innate mechanisms can lead to increased disease resistance in invertebrates. A further aquaculture development, a creation of a knowlege vaccine platform aiming to develop prophylactic measures to Indian major carps and seabass, Atlantic cod and halibut, Atlantic salmon, and shrimp is needed. Yet, no efficient vaccines against many pathogenic bacteria and viruses are available. A likely outcome of this project will be an achievement of efficient strategies to increase disease resistance in Indian and Norwegian aquacultured fish and shellfish. The work in this project has been structured into 5 workpackages (WPs), with a great deal of interaction between them. Vaccines against bacterial diseases will be covered in WP1, while different approaches of vaccination against viral diseases are addressed in WP2. WP3 covers antigens and delivery methods while we focus on in vitro methods us ed for profiling immune responses and in vivo challenge methods in WP4. WP5 covers training and exchange of personnel between partners.