Edible vaccines: A new approach to oral immunization

Edible vaccines offer exciting possibilities for significantly reducing the burden of diseases like hepatitis and diarrhoea, particularly in developing world where storing and administering vaccines are the major problems. Edible vaccines are prepared by molecular farming using the science of genetic engineering. Selected genes are introduced into the plants. The transgenic plant is then induced to manufacture the encoded protein. Owing to its low cost, it will be suitable for developing countries like India. Edible vaccines are mucosal-targeted vaccines, which cause stimulation of both systematic and mucosal immune response. Edible vaccines are being developed for various diseases, such as measles, cholera and hepatitis B, and many more are in the process of development. Thus, they may also help to suppress autoimmune disorders such as Type-I diabetes, diarrhoea, multiple sclerosis, rheumatoid arthritis, etc. Human trials conducted by the National Institute of Allergy and Infectious Diseases (NIAID), US Department of Health and Human Services, USA show that edible vaccines are feasible. ProdiGene, a biotech company, has a patent for vaccine against, viral diseases of hepatitis and transmissible gastroenteritis virus. This review comprises methods of preparation, mechanism of action, recent developments, clinical trials and therapeutic applications of edible vaccines.