Presented By Dr. Md. Mahmudul Hasan M,Phil (Microbiology, P- I) EDIBLE VACCINES : CURRENT STATUS AND FUTURE

What is Edible Vaccine ? Edible Vaccine involves introduction of selected desired genes into plant and then inducing these altered plants to manufacture the altered protein.

How it acts ? Antigen in transgenic plant > Ingestion >Delivered by bioencapsulation >Taken up by Mcell > Pass on to the Macrophage >IgG,IgE responses > Local IgA response & Memorycells > Neutralize the attack by the real infectious agent.

Advantage and Disadvantage of different plants Potato : Advantage Easily transformed. Easily propagated. Stored for long periods without refrigeration. Disadvantage Need cooking which denature antigen.

Advantages and Disadvantages Banana Advantages Do not need cooking. Protein not destroyed even after cooking. Inexpensive. Grown widely in developing countries. Disadvantages Trees take 2-3 to mature years. Spoils rapidly after ripening.

Advantages and Disadvantages Rice Advantages Commonly used in baby food. High expression of antigen. Disadvantages Grows slowly. Requires glasshouse condition.

Advantages and Disadvantages Potato Advantage Grow quicly. Cultivate broadly. High content Vitamin-A may boost immune response. Disadvantages Spoils readily.

Clinical Trial on ETEC : 11 Volunteers were feed raw transgenic Potatoes expressing LT-B. 10 (95%) of these individuals developed neutralizing antibodies and 6 (55%)develop mucosal response.

Clinical Trial on Norwalk Virus 20 people fed with transgenic potato. 19 (95%)of them expressing Norwalk virus antigen showed seroconversion.

Clinical Trial on Hepatitis B First human trials of potato-based vaccine against Hepatitis B have reported encouraging results. The amount of HBsAg needed for one dose could be achieved in a single potato. Levels of specific antibodies significantly exceeded the protective level of 10mIU/mL in human.

Advantages of Edible Vaccine Cost effective. Easy to administer. Easy to store. Acceptable to poor developing country. Fail safe Activate both mucosal and systemic immunity. Heat stable. Do not required cold chain maintenance. No fear of contamination.

Future of Edible Vaccine Resistance to GM foods may affect future of Edible Vaccine.

Limitation Transgenic contamination can occur. Antibiotic resistance marker genes can spread from GM food to pathogenic Bacteria. Difficulty in dose maintenance.

Conclusion Edible plant derived vaccine may lead to a future of safer and more effective immunization.