Norwalk virus vaccine

The disease is generally self-limiting. Oral fluid and electrolyte replacement should be used, if necessary. An oral Norwalk virus vaccine produced via expression of viral antigens in plants is under investigation, but the clinical availability of such a product is several years in the future. 

Tacket CO, Mason HS, Losonsky G, et al. Human immune responses to a novel Norwalk virus vaccine delivered in transgenic potatoes. J. Infect. Dis., 2000 182(1) 302-305. 

The most widely studied therapeutic proteins produced in plants include monoclonal antibodies for passive immunotherapy and antigens for use as oral vaccines [40]. Antibodies against dental caries, rheumatoid arthritis, cholera, E. coli diarrhea, malaria, certain cancers, Norwalk virus, HIV, rhinovirus, influenza, hepatitis B virus and herpes simplex virus have been produced in transgenic plants. However, the anti-Streptococcus mutans secretory antibody for the prevention of dental caries is the only plant-derived antibody currently in Phase II clinical trials [40]. Until recently, most antibodies were expressed in tobacco, potato, alfalfa, soybean, rice and wheat [9], It has been estimated that for every 170 tons of harvested tobacco, 100 tons represents harvested leaves. A single hectare could thus yield 50 kg of secretory IgA [3, 41]. Furthermore, it has been estimated that the cost of antibody production in plants is half that in transgenic animals and 20 times lower than in mammalian cell cul-... 

Research on other edible vaccines is in the pipeline (1) potatoes and bananas that might protect against Norwalk virus, a common cause of diarrhea, and (2) potatoes and tomatoes that might protect against hepatitis B. 

The heat-labile toxin B subunit of E. coli (LTB) [398], hepatitis B surface antigen [404], respiratory syncytial virus F protein [258], measles virus hemagglutinin [180], and Norwalk virus capsid protein [240, 405, 406] have each been successfully expressed in plants and delivered orally in animals or humans to determine their im-munoprophylactic activity. The first account of a human clinical trial of oral vaccine based on an E. coli enterotoxin as... 

Nakata S. [Vaccine development for Norwalk virus]. Nippon Rinsho, 2002 60(6) 1222-1227. 

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