Vaccines are biological preparations that improve immunity to particular diseases. They contain agents that resemble disease-causing microorganisms and stimulate the immune system to recognize and destroy them. Edward Jenner developed the smallpox vaccine in 1796 by inoculating a boy with cowpox to produce immunity to smallpox. There are several types of vaccines including live attenuated, inactivated, subunit, toxoid, conjugate, DNA, and recombinant vector vaccines. Vaccines are administered through various routes and provide both primary and secondary immune responses. They have played a crucial role in reducing disease burden globally.

1. S U B M I T T E D TO : D R . J AV E D A L I
S U B M I T T E D B Y: D I P A K K U M A R G U P T A
M . P H A R M 1 S T Y R . ( Ⅱ S E M )
P H A R M A C E U T I C S , J A M I A H A M D A R D
VACCINES

2. INTRODUCTION
 A vaccine is a biological preparation that improves immunity to a
particular disease.
 A vaccine typically contains an agent that resembles a disease-causing
microorganism and is often made from weakened or killed forms of the
microbe.
 The agent stimulates the body's immune system to recognize the agent
as foreign, destroy it, and keep a record of it.
 So that the immune system can more easily recognize and destroy any
of these microorganisms that it later encounters.
 The terms vaccine and vaccination are derived from Variolae vaccinae
(smallpox of the cow), the term devised by Edward Jenner to denote
cowpox.

3. HISTORY
 During the late 1760s whilst serving his apprenticeship as a surgeon
Edward Jenner learned of the story, common in rural areas, that dairy
workers would never have the often-fatal or disfiguring disease
smallpox.
 Because they had already had cowpox, which has a very mild effect in
humans. Edward Jenner
 In 1796, Jenner took pus from the hand of a milkmaid with cowpox,
scratched it into the arm of an 8-year-old boy.
 Six weeks later inoculated the boy with smallpox, afterwards observing
that he did not catch smallpox.
 Jenner extended his studies and in 1798 reported that his vaccine was
safe in children and adults.
 The second generation of vaccines was introduced in the 1880s by Louis
Pasteur who developed vaccines for chicken cholera and anthrax.
 From the late nineteenth century vaccines were considered a matter of
national prestige, and compulsory vaccination laws were passed. Louis
Pasteur

4. PROPERTIES
 Properties of an ideal vaccine (easy to define, difficult to achieve)
 Give life long immunity
 Broadly protective against all variants of organism
 Prevent disease transmission
 Rapidly induce immunity
 Effective in all subjects (the old & very young)
 Transmit maternal protection to the foetus
 Require few immunisations to induce protection
 Not need to be administered by injection (oral, intranasal,
transcutaneous)
 Stable, cheap & safe

5. TYPES OF IMMUNITY

6. PRIMARY & SECONDARY ANTIBODY RESPONSES
 Vaccination and infection

7. TYPES OF VACCINES
1. Live, attenuated vaccines
2. Inactivated vaccines
3. Subunit vaccines
4. Toxoid vaccines
5. Conjugate vaccines
6. DNA vaccines
7. Recombinant vector vaccines

8. ROUTES OF ADMINISTRATION
 Deep subcutaneous or intramuscular route (most vaccines)
 Oral route (sabine vaccine, oral BCG vaccine)
 Intradermal route (BCG vaccine)
 Scarification (small pox vaccine)
 Intranasal route (live attenuated influenza vaccine)
 Scheme of immunization
1. Primary vaccination
 One dose vaccines (BCG, variola, measles, mumps, rubella, yellow
fever)
 Multiple dose vaccines (polio, DPT, hepatitis B)
2 .Booster vaccination
 To maintain immunity level after it declines after some time has
elapsed (DT, MMR).

9. LIVE, ATTENUATED VACCINES
 Live, attenuated vaccines contain a version of the living microbe that
has been weakened in the lab so it can’t cause disease.
 Because a live, attenuated vaccine is the closest thing to a natural
infection, these vaccines are good “teachers” of the immune system.
 They have lost their capacity to induce disease but retain their
immunogenicity.
 Administration orally, intradermal, intranasal, subcutaneous .
 Example: Vaccines against measles, mumps, and chickenpox, small pox
Vibrio ,Salmonella , BCG, Polio, JE, Yellow Fever Influenza , MMR.

10. CONTD...
ADVANTAGES
• stimulate generation of cellular as well as humoral immune
responses.
• Since these can multiply in the host, single administration of
vaccine produce long-lived immunity.
• Multiple booster doses may not be required
• Oral preparations are less expensive than giving injections.
• elimination of wild type virus from the community
DISADVANTAGES
• May very rarely convert to its virulent form and cause disease.
• Live vaccines cannot be given to immuno-suppressed
individuals,can cause serious illness or death in the vaccine
recipient.
• Since they are live and because their activity depends on their
viability, proper storage is critical.

11. 1)LIVE ATTENUATED ,2) INACTIVATED VACCINES

12. INACTIVATED VACCINES
 When it is unsafe to use live microorganisms to prepare vaccines, they
are killed or inactivated.
 Organisms are killed or inactivated by treatment with using heat,
formaldehyde or gamma irradiation so that they cannot replicate at all,
but remain antigenic.
 Such vaccines are more stable and safe but less effective than live
attenuated vaccines.
 Because dead microbes can’t mutate back to their disease-causing state.
 route of administration Intramuscular(IM), Sub- cutaneous(SC)
 Examples: Salmonella typhi, Vibrio cholerae, Yersinia pestis,
Bordetella pertussis, Poliomyelitis Salk, JE virus, Rabies virus,
Influenza virus, Hepatitis A

13. CONTD...
 ADVANTAGES
• Safe to use and can be given to immuno-deficient and pregnant
individuals.
• Cheaper than live attenuated vaccine
• Storage not as critical as live vaccine
 DISADVANTAGES
• microorganisms cannot multiply so periodic boosters must be given to
maintain immunity.
• Only humoral immunity can be induced.
• Most killed vaccines have to be injected.
• Some vaccines such as Bordetella pertussis induce ill effects like post-
vaccinial encephalomyelitis.
• Inactivation, such as by formaldehyde in the case of the Salk vaccine,
may alter antigenicity.

14. SUBUNITS VACCINES
 Instead of the entire microbe, subunit vaccines include only the antigens
that best stimulate the immune system.
 In some cases, these vaccines use epitopes the very specific parts of the
antigen that antibodies or T cells recognize and bind to.
 Because subunit vaccines contain only the essential antigens and not all the
other molecules that make up the microbe.
 Subunit vaccines contain purified antigens instead of whole organisms.
 Such a preparation consists of only those antigens that elicit protective
immunity.
 Subunit vaccines are composed of toxoids, subcellular fragments, or
surface antigens
 The effectiveness of subunit vaccines in increased by giving them in
adjuvants.
 Route of administration Intramuscular

15. CONTD...
 Examples: Cell wall polysaccharide (Hemophilus influenzae,Nesseria
meningitides, Streptococcus pneumoniae, Group B Streptococcus
,Salmonella typhi) Toxoid (Tetanus, Diphtheria) Membrane proteins
(Influenza virus, HepatitisB), Plague immunization
 ADVANTAGE
• Scan safely be given to immuno-suppressed people
• less likely to induce side effects.
 DISADVANTAGES
• Antigens may not retain their native conformation, so that antibodies
produced against the subunit may not recognize the same protein on the
pathogen surface.
• Isolated protein does not stimulate the immune system as well as a whole
organism vaccine.

16. TOXOID VACCINES
 For bacteria that secrete toxins, or harmful chemicals, a toxoid vaccine
might be the answer.
 These vaccines are used when a bacterial toxin is the main cause of
illness.
 Scientists have found that they can inactivate toxins by treating them
with formalin. Such “detoxified” toxins, called toxoids, are safe for use
in vaccines.
 Example: Crotalus atrox toxoid is used to vaccinate dogs against
rattlesnake bites.

17. CONJUGATE VACCINES
 Is a type of vaccine that is created by joining an antigen to a protein
molecule.
 usually used to immunize babies and children against bacteria that have
polysaccharide capsular
 Polysaccharide coatings disguise a bacterium’s antigens so that the
immature immune systems of infants and younger children often have
difficulty in recognizing certain antigens, so ordinary vaccines may not be
effective for some diseases.
 A conjugate vaccine, therefore, usually consists of a polysaccharide antigen
combined with a carrier protein.

18. CONTD.....
 The combination of the antigen with the protein creates a substance
that is more easily recognizable to the white blood cells in the human
blood, resulting in a stronger immune response.
 Examples: Tetramune vaccine,which combines the tetanus and
diphtheria toxoids, whole-cell pertussis vaccine, and H. influenzae type
B conjugate vaccine.

19. RECOMBINANT VECTOR VACCINES
• The vaccines are produced using recombinant DNA technology or
genetic engineering.
 Recombinant vector vaccines are experimental vaccines similar to DNA
vaccines
 Recombinant vaccines are those in which genes for desired antigens of a
microbe are inserted into a vector.
 But they use an attenuated virus or bacterium to introduce microbial
DNA to cells of the body.
 “Vector” refers to the virus or bacterium used as the carrier.
 Examples: Hepatitis B, Diptheria, Cholera, Tetanus,

20. RECOMBINANT VACCINES

21. CONTD....
 ADVANTAGES
 Those vectors that are not only safe but also easy to grow and store can
be chosen.
 Antigens which may cause damaging responses can be eliminated from
the vaccine.
 Example :Cholera toxin A can be safely removed from cholera toxin.
 DISADVANTAGES
 Since the genes for the desired antigens must be located, cloned, and
expressed efficiently in the new vector, the cost of production is high.
 When engineered vaccinia virus is used to vaccinate, care must be
taken to spare immunodeficient individuals.

22. DNA VACCINES
 DNA vaccines are being hailed as the most promising of all of the
newer approaches to immunization.
 These vaccines are still in experimental stage , these vaccines show
great promise, and several types are being tested in humans.. Like
recombinant vaccines, genes for the desired antigens are located and
cloned.
 These vaccines dispense with both the whole organism and its parts
and get right down to the essentials: the microbe’s genetic material.
 DNA vaccines have induced both humoral and cellular immunity.
 Route of administration gene gun method, intradermal, get injection
 Examples: bird flu DNA vaccine, Influenza vaccine.

23. DNA VACCINES

24. CONTD.....
 ADVANTAGES
 DNA is very stable,hence storage and transport are easy.
 DNA sequence can be changed easily in the laboratory.
 Inserted DNA does not replicate and encodes only the proteins of
interest.
 DISADVANTAGES
 Induction of autoimmune responses: anti-DNA antibodies may be
produced against introduced DNA.
 Induction of immunologic tolerance: The expression of the antigen in
the host may lead to specific non-responsiveness to that antigen.

25. ANTI-IDIOTYPIC VACCINES
 This unique amino acid structure in the antibody is known as the
idiotype, which can be considered as a mirror of the epitope in the
antigen.
 Antibodies can be raised against the idiotype by injecting the antibody
into another animal.
 This anti-idiotype antibody mimics part of the three dimensional
structure of the antigen. This can be used as a vaccine.
 When the anti-idiotype antibody is injected into a vaccine, antibodies
(anti-idiotype antibodies) are formed that recognize a a structure
similar to part of the virus and might potentially neutralize the virus.

26. CONTD....
 ADVANTAGES:
 Antibodies against potentially significant antigen can be produced.
 DISADVANTAGES:
 Only humoral immunity is produced. There is no cellular immunity
and poor memory. Identification and preparatistructure similar to part
of the virus and might potentially neutralize the virus.

27. VACCINATION FOR TRAVELLERS
 Varies according to the country of arrival and departure.
 Common vaccines according to the country traveled to:
 TAB, YF, cholera, meningiococcal, pneuomococcal,
 HIB, influenza, rabies, plague, Japanese encephalitis,
 tickborn encephalities, measles, Hepatitis B,
 Hepatitis A, Tetanus, poliomyletis,Typhoid,
 Hajj for instance necessates meningococcal vaccination from all over
 Yellow Fever from places like south Africa, and cholera from places like
India.
 Vaccines against bioterrorism
 Anthrax
 Small pox
 Plague

28. HAZARDS OF IMMUNIZATION
 No immune response is entirely free from the risk of adverse reactions
or remote squeal.
 The adverse reactions that may occur may be grouped under the
following heads:
 Reactions inherent to inoculation
 Reactions due to faulty techniques
 Reactions due to hypersensitivity
 Neurological involvement
 Provocative reactions and Others

29. REFERENCES
 World Health Organisation http://www.who.int/topics/vaccines/en/
 A federal government Website managed by the U.S. Department of
Health and Human Services
 http://www.vaccines.gov/more_info/types/
 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1810383/
 http://www.niaid.nih.gov/topics/hivaids/research/vaccines
/Pages/default.aspx
 http://www.ncbi.nlm.nih.gov/pubmed/19208455