This document provides information about edible vaccines. It begins by defining an ideal vaccine and then defines vaccines in general. It introduces the concept of edible vaccines, which are genetically engineered foods that express vaccine antigens to provide immunity. The document discusses the mechanisms of action, methods for transforming DNA into plants, candidate plant species, examples, factors affecting efficacy, applications, limitations, regulatory issues, recent discoveries, advantages and disadvantages, and future aspects of edible vaccines.

1. Name :- Bhadani Smit Ramjibhai
Roll No.:- 17BPH095
Batch:- E
Program:- B. Pharm
Sem.:-IV
Subject:- Pharmacognosy and Phytochemistry-1

2. CONTENTS
• Introduction To Vaccines
• Ideal Vaccine
• Introduction To Edible Vaccines
• Concept Of Edible Vaccine
• Why Edible Vaccines Are Used ?
• Mechanism Of Action
• Methods For Transformation Of DNA/Gene Into Plants
• Candidates For Edible Vaccines
• Examples Of Edible Vaccines
• Consideration Factors/Factors Affecting Efficacy Of Edible Vaccines
• Application
• Limitations
• Regulatory Aspects/Issues
• Recent Discoveries
• Advantages & Disadvantages
• Future Aspects

3. IDEAL VACCINE
• It should not be toxic or pathogenic.
• Low levels of side effect.
• Long lasting humoral and cellular immunities.
• It should not contaminate the environment.
• It should not cause problems in individual.
• Technique of vaccination should be simple.
• It should be cheap.

4. VACCINES
• A vaccine is a biological preparation
that improves immunity to a particular
disease.
• It contains an agent that resembles a
disease-causing microorganism and is
often made from weakened or killed
forms of the microbes, its toxins or one
of its surface proteins.
• The process of distributing and
administrating vaccines is referred to as
vaccination. Vaccination is a form of
immunization.
• Routes of administration, including
oral, nasal, intramuscular, subcutaneous,
and intradermal.
VACCINES
PROPHYLACTIC
(e.g. to prevent the
effects of a future THERAPEUTIC
infection by any (e.g. vaccines against
Natural or “ wild” cancer).
pathogen )

5. EDIBLE VACCINES
• A genetically manipulated food, containing organisms or related antigens that
may provide active immunity against infection.
• In the edible vaccines Transgenic plants are used as vaccine production
systems.
• The genes encoding antigens of bacterial and viral pathogens can be expressed
in the plants in a form in which they retain native immunogenic properties.
• Initially thought to be useful only for preventing infectious diseases, it has
to be found application in prevention of autoimmune diseases, birth
control, cancer therapy, etc.
• Edible vaccines are currently being developed for a number of human and
animal diseases.
• As Hippocrates said, Let “ thy food be thy medicine”.

6. CONCEPT OF EDIBLE VACCINES
Developed by Arntzen in the 1990s.
Introduce gene of interest into plants(Transformation)
Gene expressed in the plant tissues edible parts (Transgenic plants)
Genes encode putatively protective vaccine antigens form viral, bacterial, and
parasitic pathogens that cause disease in humans and animals
Ingestion of the edible part of the transgenic plant (oral delivery of vaccines).

7. WHY EDIBLE VACCINES USED?
NEEDLE FREE
CHEAP
STORAGE
SAFE
Oral vaccines provide “mucosal immunity” at various sites by
secreting antibodies.
Don’t need to worry about re-use, misuse and lack of
sterilization. Thus, low risk of infection .
Estimated cost of $0.005 to grow antigen for one dose of
hepatitis B vaccine in an unprocessed form.
Administering oral vaccines would require little or no training
at all.
Heat-stable; do not require cold-chain maintaince.
If the local/native crop of a particular area is engineered to
produce the vaccine, then the need for transportation and
distribution can be eliminated.

8. MECHANISM OF ACTION
 The goal of oral vaccination is to stimulate the mucosal and systemic immunity against
pathogen.
• Edible vaccine when taken orally undergoes the mastication process and the
majority of plant cell degradation occur in the intestine as a result of action of
digestive or bacterial enzyme on edible vaccine.
• Peyer’s patches (PP) are an enriched source of IgA producing plasma cells
and have the potential to populate mucosal tissue and serves as mucosal
immune effector site.
• The breakdown of edible near PP, consisting of the 30-40 lymphoid nodules
on the outer surface of intestine and contain follicles.
• These follicles act as the site from which antigen penetrates the intestinal
epithelium, thereby accumulating antigen within organized lymphoid structure.
• The antigen then comes in contact with M-cell.
• M -cell passes the antigen to macrophages and B-cell.

10. HOW EDIBLE VACCINES PROVIDE
PROTECTION

11. METHODS FOR TRANSFORMATION
OF GENES INTO PLANTS
STABLE INTEGRATION TRANSIENT EXPRESSION
ELECTRO
PORATION
VECTOR CARRIER
METHOD
MICROPROJECTILE
BOMBARDMENT
METHOD
CHIMERIC
VIRUSES

13. PLASMID/VECTOR CARRIER SYSTEM:
Agrobacterium Tumifaciens METHOD

14.  MICRO PROJECTILE
BOMBARDMENT/GENE
Selected DNA sequences are precipitated onto metal (e.g. Gold, tungsten)
particle
Bombarded against the vegetable tissue with a particle gun at an accelerated
speed
Micro-particles penetrate the walls and release the exogenous DNA inside the
cell where it will be integrated in the nuclear genome
Produce large number of genetically identical crop

15.  MICRO PROJECTILE
BOMBARDMENT/GENE
c

16. CHIMERIC VIRUSES METHOD

17. ELECTRO- PORATION
• Introduction of DNA into cells by exposing them for brief period to high
voltage electrical pulse which is thought to induce transient pores in the plasma
lemma.
• The cell wall presents an effective barrier to DNA. Therefore, it has to be
weakened by mild enzymatic treatment so as to allow the entry of DNA into
cell cytoplasm.

18. FACTORS AFFECTING EFFICACY OF
EDIBLE VACCINES
FACTORS
AFFECTING
EDIBLE
VACCINES
Antigen selection (safe, suitable, stable)
Efficacy in model systems (small qty.)
Choice of plant species (suitable, easy grown, storage, cost)
Delivery and dosing issues
Safety issues (allergic & toxic potential)
Public perceptions and attitudes to genetic modification
Quality control and licensing (consistent)

19. CANDIDATE PLANTS
BANANA POTATO TOMATO
RICE
MAIZE TOBACCO WHEAT CARROT

20. EXAMPLES OF EDIBLE VACCINES

21. APPLICATIONS
• Cancer Therapy.
• Birth Control.
• Chloroplast Transformation.
• Role In Auto Immune Disease.
• Recombinant Drugs/Proteins.

22. LIMITATIONS
• Individual may develop immune tolerance to the particular vaccine protein
or peptide.
• Dosage required varies from generation to generation and plant to plant
,protein content, patent’s age, weight.
• They are prone to get microbial infestations.
• Selection of best plant is difficult.
• It’s function can be hampered due to vast difference in the glycosylation
pattern of plants and humans.

23. LIMITATIONS
• They are dependent on plant stability as certain foods cannot be eaten
raw (e.g. Potato) and needs cooking that cause denaturation or
weaken protein present.
• Proper demarcation line is necessary between ‘vaccine fruit’ and
‘normal fruit’ to avoid misadministration of vaccines.

24. REGULATORY ASPECTS
• It has to be decided whether edible vaccines wouldberegulated under food, drugs or
agricultural products.
• Undecided that licensing shall be required for the antigen or genetically engineered
fruit or transgenic seeds.
• Transgenes may spread by pollen, sucking insects, transfer to soil microbes during
plant wounding or breakdown of roots and may pollute surface and ground water.
• Ethical considerations usually restrict clinical trials from directly assessing protection in
humans.

25. ADVANTAGES
• Do not require administration by injection.
• Possible production of vaccines with low costs.
• Do not require separation and purification of vaccines from plant materials.
• Necessary syringe & needles not required.
• Economical in mass production and transportation.
• Heat stable, eliminating the need for refrigeration.

26. DISADVANTAGES
• Development of immune tolerance to vaccine peptide or protein.
• Consistency of dosage from fruit-to-fruit, plant-to-plant and generation- to - generation
not
similar.
• Stability of vaccine in fruit is not known.
• Dosage of vaccines would be variable.
• Selection of best plant is difficult.
• Certain foods like potato are not eaten raw, and cooking the food might weakens the
medicine present in it.
• Not convenient for infants.

27. RECENT DISCOVERIES
 Scientists Create Edible Honeybee Vaccine To
Protect Them From Diseases:-
• “The first ever vaccine for insects now exists.
Scientists at University of Helsinki in Finland
hoping to save honeybee worked on it. This
Edible vaccine protects the bees against
American foulbrood(a bacterial disease caused
by spore-forming Paenibacillus larvae
ssp.Larvae. This will help to protect the global
food production honeybees.”
- 1st January,2019

28.  NATURAL COMPOUNDS FIGHT AGAINST ZIKA
AND DENGUE VIRUS
• “National University Singapore have discovered that many edible plants
contain natural compounds that can protect us from Zika and Dengue virus.
The university said that many natural compounds can disrupt the replication
machinery of both zika and dengue virus. They are present in foods like tea,
red onion, yellow ginger and grapes. In future the research team plans to test
this vaccine .”
-5th October,2018

29. FUTURE ASPECTS
• Edible vaccine holds a greatpotential.
• It reduces the cost of transportation andrefrigeration.
• It neglect the needle and complicated way of vaccine administration.
• For many disease the research in going on in manycountries funded by their
government or industry.
• Significant challenges are still to be overcome beforevaccine crop can become a
reality.
• There are some safety concerns which need to be overcomein near future.
• In another concern, scientists need to be sure thatvaccines meant to enhance
immune response do not backfire and suppress immunity instead.