Edible vaccines

vaccines

1. Edible vaccines

2. Title and Content Introduction to edible vaccines Advantages of edible vaccines Limitations and characterization Mechanism Edible algae vaccine Examples of edible vaccines Future prospects

3. Introduction to edible vaccines

4. INTRODUCTION Edible Vaccine - A great boon in medicinal science. Biotechnologists in recent years have come up with a new concept. This new concept is about edible vaccine. Idea of edible vaccines was given by Arntzen in 1990’s when he saw a mother presenting his crying child with a banana, eight years before he claimed that edible vaccines are easy to use and is beneficial against many diseases. Development of edible vaccines is a possible high-volume, low-cost delivery system for third-world countries to fight against fatal maladies like AIDS, hepatitis and diarrhea.

5. Edible Vaccines have many potential advantages Edible plants are very effective as a delivery vehicle for inducing oral immunization. Adjuvant for immune response is not necessary. Excellent , feasibility of oral administration compared to injection, no disease transformation. Effective prevention of pathogenic contamination from animal cells. Convenience and safety in storing and transporting vaccines. Easy for mass production system by breeding compared to an animal system. possible production of vaccines with low costs.

6. BENEFITS Economical to mass produce and transport. Reduced dependence on foreign supply. Storage near the site of use. Heat stable, eliminating the need for refrigeration. Antigen protection through bioencapsulation, as the digestive enzymes will not degrade the insert. Subunit vaccine (not attenuated pathogens) means improved safety.

7. LIMITATIONS Producing stable and reliable amounts of vaccines in plants is complicated by the fact that tomatoes and bananas don’t come in standard sizes! There may also be side-effects due to the interaction between the vaccine and the vehicle. People could ingest too much of the vaccine, which could be toxic, or too little, which could lead to disease outbreaks among populations believed to be immune.

8. CHARACTERISTICS No Serious Side Effects : volunteers has been checked and there is no side effects of eatable vaccines. Reduced Anaphylactic Risk: Reduced risk of anaphylactic side effects from edible vaccine over injection systems is one benefit reported by the it has been reported that edible vaccine carries only part of the allergen compared to injection methods that reduce anaphylactic risk.

9. MECHANISM The antigens in transgenic plants are delivered through bio-encapsulation, i.e. the tough outer wall of plant cells, which protects them from gastric secretions and finally break up in the intestines. The antigens are released, taken up by M cells in the intestinal lining that overlie peyer's patches and gut-associated lymphoid tissue (GALT), passed on to macrophages, other antigen-presenting cells; and local lymphocyte populations, generating serum IgG, IgE responses, local IgA response and memory cells Now it would promptly neutralize the attack by the real infectious agent.

10. Examples and future prospects of edible vaccine

11. Edible algae vaccine Edible algae based vaccination is a developing vaccination strategy It combines a genetically engineering sub-unit vaccine and an immunologic adjuvant into  Chlamydomonas reinhardtii  micro algae. Micro algae can then be freeze dried and administered orally.  All current edible algal vaccines still reside in pre-clinical trials. Due to the relatively low production cost of algal growth, the completion of a market ready edible algae vaccine would have a profound impact in the administration and distribution of immunizations in impoverished populations.

12. PLANTS USED FOR EDIBLE VACCINE Tobacco Potato Banana Tomato Rice Lettuce Soybean Alfalfa Carrot Peanuts Wheat corn

13. PLANT SPECIES Potato : Advantage Easily transformed. Easily propagated. Stored for long periods without refrigeration. Disadvantage: Need cooking which denature antigen Banana: Advantages Do not need cooking. Protein not destroyed even after cooking. Grown widely in developing countries. Disadvantages Trees take 2-3 to mature years. Spoils rapidly after ripening.

14. PLANT SPECIES Rice Advantages Commonly used in baby food High expression of antigen. Disadvantages Grows slowly. Requires glasshouse condition Tomato Advantage Grow quickly. Cultivate broadly. High content Vitamin-A may boost immune response. Disadvantages Spoils readily

15. EXAMPLES MALARIA: Three antigens are currently being investigated for the development of a plant-based malaria vaccine. merozoite surface protein (MSP) 4 and MSP 5 from Plasmodium falciparum, and MSP 4/5 from P. yoelli . It has been demonstrated that oral immunization of mice with recombinant MSP 4, MSP 4/5 and MSP1, co-administered with CTB as a mucosal adjuvant, induced antibody responses effective against blood- stage parasite.

16. EXAMPLES MEASLES :Mice fed with tobacco expressing MV-H (measles virus hemagglutinin from Edmonston strain) could attain antibody titers five times the level considered protective for humans and they also demonstrated secretory IgA in their feces. Carrot, banana and rice are the potential candidates.   HEPATITIS B: significantly exceeded the protective level of 10 mIU /mL in humans.. potato-based vaccine against hepatitis B have reported The amount of HBsAg needed for one dose could be achieved in a single potato.

17. EXAMPLES CHOLERA: Plants were transformed with the gene encoding B subunit of the E. coli heat liable enterotoxin (LT-B). Transgenic potatoes expressing LT-B were found to induce both serum and secretory antibodies when fed to mice; these antibodies were protective in bacterial toxin assay in vitro. This is the first “proof of concept” for the edible vaccine.

18. FUTURE PROSPECTS Edible vaccine holds a great potential . It reduces the cost of transportation and refrigeration. It neglects the needle and complicated way of vaccine administration. For many disease the research in going on in many countries funded by their government or industry. Significant challenges are still to be overcome before vaccine crop can become a reality. There are some safety concerns which need to be overcome in near future. To determine safe, effective doses and feeding schedules for edible vaccines. A final issue worth studying is whether food vaccines ingested by mothers can indirectly vaccinate their babies.