Overview on Edible Vaccine: Pros & Cons with Mechanism

This ppt include the description of the edible vaccine i.e. a new concept over the traditional vaccine administered by injection.

1. EDIBLE
Vaccine
Prepared by:
Ms. Diptee Gupta
Assistant Professor
Krishna Institute of Pharmacy
& Sciences, Kanpur
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2. What is vaccine?
•A vaccine is a biological preparation that improves immunity to
a particular disease.
•It contains agent that resembles a disease-causing micro-
organism and made of killed forms of microbes.
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Ideal Properties:
•It should not be toxic or pathogenic.
•Low levels of side-effects.
•It should not contaminate the environment.
•It should not cause problems in individual.
•Technique of vaccination should be simple.
•It should be cheap.

3. concept of edible vaccine
•Also termed as food vaccines, oral vaccines, subunit vaccines, and green
vaccines
•Edible vaccines are produced by introducing the genes that encode
specific antigens from a pathogen into the genome of a plant.
•The plant produces the edible vaccine antigens in its edible parts, such as
fruits or leaves.
•When the part of the plant is consumed, the human digestive system
processes the vaccine antigens, triggering an immune response that
produces protective antibodies against the pathogen.
•Edible vaccines can be very easily scaled up.
•For example, the entire population of China could be vaccinated by
producing edible vaccines in just 40 hectares of land.
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4. history of edible vaccine
•The first report of edible vaccine ( surface protein from Streptococcus) in
tobacco, at 0.02% of total leaf protein, appeared in 1990 as a patent
application published under the international patent cooperation treaty.
•In the 1990, Dr. Charles Arntzen and his coworker introduced the concept
of transgenic plants as a product delivery system for subunit vaccines in
which edible use of transgenic crop plants was used.
•They found that this concept could overcome the limitations of traditional
vaccines.
• In 1990s, Streptococcus mutans surface protein antigen A was expressed for
the first time in tobacco.
•The same group also done research work on hepatitis B and heat-labile
toxin, B subunit in tobacco plants and potato tubers.
•In the same year, the successful expression of hepatitis B surface antigen
(HBsAg) in tobacco plants was also achieved.
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5. introduction
•In edible vaccine, transgenic plants are used as vaccine productive system.
•The gene encoding antigens of bacterial and viral pathogens can be expressed
in plants in form in which they retain native immunogenic properties.
•A protein which acts as the vaccine, present in food and consumed as the
internal composition of food is known as edible vaccine.
•Edible vaccines are produced from one edible part of plants, such as fruits
and vegetables, that can be ingested orally rather than injected like
traditional vaccine.
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**Transgenic plants are the ones, whose DNA is
modified using genetic engineering techniques.
The aim is to introduce a new trait to the plant
which does not occur naturally in the species.
Improving shelf life, higher yield, improved
quality, pest resistance, express foreign proteins
with industrial and pharmaceutical value.

6. Plants used for edible vaccine
Should have following properties:
❑Musthavelongshelflife.
❑storedforalongtimewithoutdegradationsuchasrice,maize&wheat
❑Mustgrowquicklysuchastobacco&tomatoplant.
❑Fruitsorvegetablesthatusuallyareproducedontreesarenot
considered.
❑Easytransformation.
Example of plants used for edible vaccine:
Tobacco, Potato, Banana, Tomato, Rice, Lettuce, Soybean, Alfalfa, Carrot,
Peanuts, Wheat, and Maize.

7. Examples of edible vaccines
•Transgenic Potatoes For Diarrhoea
The first human trial for an edible vaccine took place in 1997.
Volunteers ate transgenic potatoes that contained the b-subunit of
the E. coli heat-labile toxin, which causes diarrhoea. Ten of the 11
volunteers showed a 4-fold increase in serum antibodies.
•Transgenic Tomatoes Against Diarrhoea
Scientists have developed transgenic tomatoes against the Norwalk
virus, which causes severe diarrhoea. The tomatoes produced a
surface protein specific to the virus. Mice that ate these tomatoes
developed an immune response to the virus.
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8. Mechanism of action
•The breakdown of edible
vaccine consisting of 30-40
lymphoid nodules on the outer
surface of intestine and contains
follicles.
•These follicles act as the site
from which antigen penetrates
the intestinal epithelium,
accumulating antigen within
organized lymphoid structure.
•The antigen comes in contact
with M-cell.
•M-cell passes the antigen to
macrophages and B-cell
activates the T-cell to provide
immune response.
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It stimulate the mucosal and systemic immunity against pathogen. The MIS is the
first line of defense as it is where human pathogens initiate their infection.
Mucosal surfaces are found lining the digestive tract, respiratory tract, and urino-
reproductive tract

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10. Advantage of Edible vaccine
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They trigger the immunity at the mucosal surfaces such as those that line
the mouth (mucosal immunity) which is the body’s first line of defence and
alsosystemicimmunity.
✓Ediblemeansofadministration.
✓Noneedofmedicalpersonnelandsyringes.
✓Economicalinmassproductionbybreedingcomparedtoananimal
system.
✓Easyforadministrationandtransportation.
✓Effectivemaintenanceofvaccineactivitybycontrollingthetemperature
inplantcultivation.
✓Heatstable,thuseliminatingtheneedofrefrigeration.
✓Noserioussideeffectproblemshavebeennoticeduntilnow.
✓Reducedriskofanaphylacticsideeffectsfromediblevaccineover
injectionsystem

11. Limitation of Edible vaccine
✓Consistencyofdosagefromfruittofruit,planttoplant,lottolot,
andgenerationtogenerationisnotsimilar.
✓Stabilityofvaccineinfruitisnotknown.
✓Evaluationofdosagerequirementistedious.
✓Selectionofbestplantisdifficult.
✓Notconvenientforinfants
✓Peoplecouldingesttoomuchofthevaccine,whichcouldbe
toxic,ortoolittle,whichcouldleadtodiseaseoutbreaks.
✓Certainfoodslikepotatoesaregenerallynoteatenrawand
cookingthefoodmightweakenthemedicinepresentinit
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