Oral delivery of encapsulated viral antigens to Atlantic salmon

A range of viral pathogens currently present a significant challenge to Atlantic salmon operations globally. Injection vaccines are used commercially against a number of virus, but these are not available for small fish and protection may decline some mon ths after seawater transfer. The development of effective oral vaccines would allow small fish to be protected as well as providing the ability to boost the immune system of larger fish. This could significantly increase operational flexibility as well as reduce losses from viral pathogens. Oral vaccines have not been successful in aquaculture operations. They may be denatured during feed production process as well as the digestive system within the fish. Uptake across the gut may be limited and the lar ge quantities of vaccine required have made them uneconomic. The following programme will assess oral delivery systems that can protect the antigens against the digestive process of fish. These delivery systems will be deployed at optimal phases of the fe ed production process. Alginate and mesoporous silica will be used to encapsulate viral antigens of Infectious Salmon Anemia (ISA) and Infectious Pancreatic Necrosis (IPN) Virus. In vitro assays will assess survival of encapsulated antigens through adv erse temperatures, pH and enzymatic activity. Immune assessments will determine antigen uptake in vivo and compare oral delivery with anal and oral intubation. Protection will be determined under controlled challenge.