Edible Transgenic Plant Vaccines – An Overview and Update

Abstract

Plants are used as bioreactors to express antigenic molecules to be administered as vaccines. Edible transgenic plant vaccines (ETPV) are plant materials (recombinant protein subunit vaccines), and the edible plant tissue functions as an oral vaccine. ETPV are mucosal targeted vaccines where stimulation of both systematic and mucosal immune network takes place and these diminish the utilization of conventional animal or bacterial systems. These are prepared by using transgenic plants that express antigen proteins capable of inducing protective immunity against various human and animal diseases to induce specific immune responses. Edible vaccine candidates have been produced in a variety of plant species, including potato, corn, tomato, carrot, lettuce, watermelon, rice, spinach, and much more. A number of clinical trials have produced encouraging results and ETPV offer exciting opportunities for significantly reducing the burden of diseases like hepatitis, cholera and measles, autoimmune disorders like diabetes mellitus-type I, diarrhoea, multiples sclerosis, and rheumatoid arthritis.

 However, ETPV have a long way to go before they will be ready for large-scale tests in humans and animals for the fight against infectious diseases. Experts are of the opinion that the future of edible vaccines will depend on the production of  sufficient quantities, and further, if future clinical trials prove successful, the advantages of edible vaccines would be enormous, especially for developing countries. Furthermore, ETPV may be useful, but the risks to human health and the environment are to be checked.