Plant Vaccines

Transgenic plants may express immunogenic proteins, which by consuming the plant tissues by humans or animals, may protect against bacterial or viral diarrhea. Also, plant synthesized immunoglobulins may protects against Streptomyces mutans, responsible for dental caries and gum disease. Hepatitis B surface antigen (HBsAg), Norwalk virus capsid protein (NVCP), E. coli heat-labile enterotoxin B subunit (LT-B), cholera toxin B subunit (CT-B), and mouse glutamate decarboxylase (GAD67) have been propagated in tobacco and potato tissues, respectively. Hepatitis B vaccine delivered by raw potatoes-when a sufficient quantity was consumed-increased the serum antiHB surface antigen titer in up to 62.5% of the volunteers (Thanavala Y et al 2005 Proc Natl Acad Sci USA 102:3378). So far, these edible vaccines have not shown clinical use. The S1 protein of the SARS corona virus propagated in tomato and tobacco plants displayed good immunogenicity in mice after both parenteral (injection)