Spirulina-based oral vaccine for infectious hematopoietic necrosis virus (IHNV) in farmed salmonid fish

Non-Technical SummaryAquaculture is the fastest growing segment of the global food industry and plays an increasingly important role in feeding the world's population. Intensive aquaculture using increased stocking densities, compressed rearing cycles, monocultures, antibiotics, and other strategies aimed at efficient protein production has been complicated by outbreaks of known and newly emergent pathogens, often with devastating consequences. IHNV, the virus that is targeted in this proposal, has spread worldwide from its origin in North America, and its danger is illustrated by a recent outbreak in the Canadian salmon farming industry that was estimated to have caused $200 million in lost sales in a single year. Vaccination is far and away the most effective and cost effective approach to limiting pathogen outbreaks, though the present technology is costly, cumbersome and potentially unsafe for both producers and consumers.Lumen Bioscience has invented and developed technology that allows the genetic manipulation of the widely consumed algae Spirulina. Spirulina is very high in protein and micronutrients and is consumed by humans and fed to their animals globally. This valuable food crop has resisted genetic manipulation despite decades of effort until Lumen scientists discovered the means to manipulate the organism, much as is done with other food crops. Lumen scientists are able to insert or remove genes from Spirulina, allowing optimization of its growth and the use of Spirulina to produce proteins it otherwise would not. One such protein safely and potently stimulates the immune system, creating "memory", which is the essential feature of an effective vaccine.Using Spirulina to generate vaccine proteins, combined with the delivery of such vaccine-bearing nutritious algae in the form of food, offers a number of potent advantages, not least being the avoidance of trauma to the fish, cost savings and safety for fish farm workers, and the absolute avoidance of fish products contaminated with needle fragments or other debris from the conventional vaccination process. Initial data generated at Lumen indicate that the inert vaccine protein we have designed, bearing structures from the IHN virus, is recognized by the fish immune system much like the actual IHN virus is. We will administer the vaccine-bearing algae to fish via their digestive system, to mimic eating vaccine-laden food pellets, and assess whether a protective vaccine response is induced. Positive findings in these experiments will lay the groundwork for further optimization of both the vaccine particle design, and the use of Spirulina for this and other vaccine and therapeutic applications, for both human and animal health goals.