Edible vaccine

Mechanism,mode of action,applications,advantages and limitations of edible vaccine.

1. EDIBLE VACCINE

2. Presented by Group No: 07 Subha Shabnam Kristy-(2014-3-76-027) Rehnuma Hossain -(2015-1-77-010) Asma Hossain -(2015-2-77-004) Fameema Tasneem -(2015-3-77-007)

3. What is Edible Vaccine ? Edible vaccine is a genetically influenced food, containing related antigens that may provide active immune response against infection and inflammation.  These are easy to apply, store and transport. It could also induce both mucosal and systematic immune responses; which cannot be achieved by using an injection vaccine.  

4. Mechanism

5. Mode of Action Oral intake of edible vaccine Breaks down at peyer’s patches (contain 30-40 lymphoid nodules containing Follicles) Antigen penetrates to follicles and accumulate In lymphoid structure. Antigen contacts M-cells that activate B-cells Within the follicles B cell leaves the follicles and gives mucosal immunity When it reaches in mucosal associated lymphoid tissue (MALT )

6. Applications of Edible vaccine Autoimmune Disease: An experiment was established for the development of plant based diabetes vaccine in potatoes and tobacco containing insulin linked to the non-toxic B subunit of the V. cholera toxin to intensify uptake of the antigen of M cells. Gastrointestinal Disorder: WHO have revealed that cholera vaccine can provide cross protection against E.coli heat labile enterotoxin (LT-B). Transgenic potatoes expressing LT-B were fed to mice and does not inactive the antigen present in edible vaccine. Malaria: Three antigens were used namely merozoite surface protein (MSP4, MSP5 and MSP4/5) to develop the malaria vaccine. When mice were orally immunized with this recombinant antigen; they show immune response. Measles: Selection of MV-H antigen is important and that is introduced in tobacco plant with the help of plasmid vector to treat measles.

7. Advantages and Limitations of Edible Vaccine ADVANTAGES : Decreased need for medical staffs. Cost effective in mass production and transportation. Swallowed by eating the plant/part of the plant Therapeutic proteins are free of pathogens and toxins. Heat stable, no need for re­frigeration. Generation of systemic and mucosal immunity. Delivery of multiple antigens. Advanced equipments and machines are not needed to produce edible vaccines as they could be easily grown. LIMITATIONS: Individuals may show resistance to vaccines. Consistency of dose may vary from fruit to fruit, plant to plant , generation to generation. Selection of best plant is difficult. People may show allergic reactions to the fruit or vegetable expressing the foreign antigen . Will the antigens be able to survive the acidic conditions of the stomach and even if they did, will they be able to trigger the immune system in the right way? Although initial trials have shown positive results in humans, it is not clear what will happen later.

8. Future Prospects Edible vaccines require approval by WHO in terms of quality, efficiency and environmental effect before supplying in the market for human usage.  Transgenic crops gained acceptance in developing countries gradually.  Edible vaccines present good economic and technological advantages as more than 350 genetically engineered products are now in progress in the USA and Canada. Hopefully, In coming future edible vaccines against smallpox, anthrax, plague and many other diseases can be produced on a huge amount within a short time period.

9. Conclusion Edible vaccines may lead to a future of safer and more effective immunization over some of the problems related with traditional vaccines. They have passed the major difficulties in the path of an emerging vaccine technology before becoming a reality.  The aim is that edible vaccines would be grown in many of the developing countries . That day is not far off when we will be able to pluck a fruit from the garden, eat it and be protected from diseases…making needles needless…