DNA vaccines work by inserting genetic code for antigens into cells, which then produce proteins that induce an immune response. They elicit both antibody and T cell responses and do not require refrigeration. Clinical trials show promise for DNA vaccines against diseases like influenza, West Nile virus, and rabies. However, safety issues around integration into the genome, autoimmunity, and antibiotic resistance must still be addressed before widespread human use. Future applications could include multi-gene vaccines against multiple diseases.

1. PRESENTED BY
B.KARTHIKEYAN

2. CONTENTS
 Introduction  Advantages
 History  Disadvantages
 DNA vaccines Vs  Clinical trials
Traditional vaccines
 How DNA vaccine is made
 Safety issues
 Methods of delivery  Future of DNA
 How DNA vaccine works vaccines
 Conclusion
 References

3. INTRODUCTION
 DNA vaccine is DNA sequence used as a
vaccine.
 This DNA Sequence code for antigenic protein of
pathogen.
 As this DNA inserted into cells it is translated to
form antigenic protein. As this protein is foreign
to cells , so immune response raised against this
protein.
 In this way ,DNA vaccine provide immunity
against that pathogen.

4. HISTORY
• In 1990, University of Wisconsin, Jon Wolff found
that injection of DNA plasmids produce a protein
response in mice.
• In 1993, Merck Research Laboratories, Dr.
Margaret Liu found that intramuscular injection of
DNA from influenzae virus into mice produced
complete immune response
• In 1996, trials involving T-cell lymphoma,
influenzae & herpes simplex virus were started

5. DNA vaccines Vs Traditional
vaccines
DNA vaccines Traditional vaccines
» Uses only the DNA » Uses weakened or
from infectious killed form of infectious
organisms. organism.
» Avoid the risk of using » Create possible risk of
actual infectious the vaccine being fatal.
organism.
» Provide both Humoral » Provide primarily
& Cell mediated Humoral immunity
immunity » Usually requires
» Refrigeration is not Refrigeration.

6. HOW DNA VACCINE IS
MADE
Viral gene
Recombinant DNA
Technology
Expression
plasmid
Plasmid with foreign gene

7. Transform into
bacterial cell
Plasmid
DNA
Bacterial cell

8. Plasmid DNA get
Amplified

9. Plasmid DNA
Purified
Ready to use

10. METHODS OF DELIVERY
Syringe delivery:-
Either
intramuscularly
or
Intradermally

11. Contd..
Gene gun delivery:-
Adsorbed plasmid DNA
into gold particles
Ballastically accelerated
into body with gene gun.

12. HOW DNA VACCINE WORKS
BY TWO PATHWAYS
ENDOGENOUS :- Antigenic Protein is presented by
cell in which it is produced
EXOGENOUS :- Antigenic Protein is formed in
one cell but presented by
different cell

13. HOW DNA VACCINES
WORK
+
Muscle Cells Plasmid DNA

14. ENDOGENOUS PATHWAY
Nucleus
Plasmid
DNA
mRNA MHC-I
Antigenic
Peptides
Antigenic
Protein

15. T- Helper Cell
Mu
lt ipl
y
Memory T cells

16. EXOGENOUS PATHWAY
Antigenic Protein come outside

17. s ed
oc yto
g
Pha
Antigen Presenting Cell
Antigenic Peptides
Memory
T- Helper Cell
Antibodies
Cytokines
Plasma B-Cell
MHC-II
Activated B-Cell Memory B-Cell

18. WHEN VIRUS ENTER IN THE BODY
Memory T-Cell
Viral Protein
Antibodies

19. ADVANTAGES
* Elicit both Humoral & cell mediated
immunity
* Focused on Antigen of interest
* Long term immunity
* Refrigeration is not required
* Stable for storage

20. DISADVANTAGES
 Limited to protein immunogen only
 Extended immunostimulation leads
to chronic inflammation
o Some antigen require processing
which sometime does not occur

21. CLINICAL TRIALS
June 2006,DNA vaccine examined on horse
Horse acquired immunity against west
nile viruses
August 2007,DNA vaccination against
multiple Sclerosis was reported as being
effective

23. Genetic Toxicity
Integration of DNA vaccine into host Genome
Insertional mutagenesis
Chromosome instability
Turn ON Oncogenes
Turn OFF Tumor suppressor genes

24. Over Expression of DNA vaccine
Acute or chronic inflammatory responses
Destruction of normal tisues

25. Generation of Autoimmune
diseases
Anti DNA Antibodies
Autoimmune diseases
Autoimmune Myositis

26. Antibiotic Resistance
 Plasmid used is resistance to
antibiotics for selection
 Raise the resistance to same
antibiotic in the host

27. FUTURE PROSPECTS
Plasmid with multiple genes provide immunity
against many diseases in one booster
DNA vaccines against infectious diseases such
as AIDS, Rabies, Malaria can be available

28. CONCLUSION
* DNA vaccines are in their early phase.
* There are no DNA vaccines in market at
present.
* But this just the beginning .
* DNA vaccines are going to be the vaccines of
next generation.

29. References
> www.medscape.com
> www.wikipedia.org
> www.sciencedirect.com
> www.nature.com
> www.biokenyon.com
> www.biolife.com
 Immunology by Kuby 6th Edition
 Immunology by Tizard 4th Edition

30. THANK YOU