Vaccines provide protective immunity and immunological memory to individuals, families and communities against any infectious disease.
Vaccines are cheap, cost – effective , easily administered and adaptable to mass vaccination.
Viral diseases can be managed through vaccination.
Immunity and Vaccine
Dr. B. Victor., Ph.D.
Email: bonfiliusvictor @ gmail.com
Kinds of immunity-natural,
acquired, active and passive
&therapeutic; monovalent &
General classes of vaccines
Vaccines of general use.
Problems in vaccine development.
Disease prevention is the key
to public health.
immunity and immunologic
memory similar to natural
infection but without the risk of
Every year vaccine prevent up
to 3 million deaths and save
750,000 children from
Kinds of immunity
Natural or Innate or
Acquired or Adaptive or
Prevents the entry of
Eliminates the antigens
antigens into the body.
No time lag
Not antigen specific
from the body.
A lag period
Active immunity refers to the process of
exposing the body to an antigen to generate
an adaptive immune response:
The response takes days/weeks to develop but
may be long lasting—even lifelong.
Active immunity is usually classified as natural or
Natural active immunity- The individual has
developed immunity to a live pathogen by
having been exposed to it.
Acquired active immunity - by vaccination
Passive immunity refers to the process of providing IgG
antibodies to protect against infection;
It gives immediate, but short-lived protection—several
weeks to 3 or 4 months.
Passive immunity is usually classified as natural or
Natural passive immunity – refers to the transfer of
maternal tetanus antibody (mainly IgG) across the
placenta provides for the newborn baby.
Acquired passive immunity- refers to the process of
obtaining serum from immune individuals.
Naturally acquired active
immunity – it occurs when the
person is exposed to a live
pathogen, develops the disease,
and develops immunity.
Artificially acquired active
immunity – It can be induced by a
vaccine, a substance that
contains the antigen.
Discovery of Vaccination
The word vaccine derived from
the word vaca, meaning a cow
Edward Jenner discovered a
vaccination for smallpox
disease in 1796.
Jenner scratched some pus
from a Cowpox sore into the
arm of a boy James Phipps to
see whether exposure to the
virus protect the child from the
Phipps was became immune,
proving that inoculation with
cowpox provided resistance
treated a boy
against rabies by
injecting spinal cord
fluid of a rabid dog.
The spinal cord fluid
the rabies virus
Louis Pasteur performed first
experiment in immunology in July
vaccination in 1796
using cowpox to
Golden age of vaccine technology –
from 1950 – 1970. During this period, vaccines
for polio, measles, mumps and rubella was
Disease prevention by vaccination
is of two types
1. Primary prevention – is an intervention before
the biologic onset of disease e.g. prevention
of infectious disease by vaccination.
2. Secondary prevention – is an intervention
when disease can be detected at a stage
before it is symptomatic e.g. AIDS.
Prophylactic and therapeutic vaccines
Prophylactic vaccines – the vaccine is used to
prevent the effects of a future infection by any
natural or wild pathogen. e.g. anti-rabies
Therapeutic vaccines – the vaccines are
devised to harness the immune response to
treat diseases ranging from cancer to multiple
sclerosis. E.g. cancer vaccine.
Monovalent and multivalent vaccines
A monovalent (univalent) vaccine is designed
to immunize against a single antigen or single
pathogen. E.g. chicken pox.
A multivalent (polyvalent) vaccine is designed
to immunize against two or more strains of the
same microorganism or against two or more
microorganisms. E.g. DTP vaccine – (Diphtheriatetanus- pertusis vaccine).
MMR vaccine – measles-mumps-rubella
Importance of immunization
Vaccines provide protective immunity and
immunological memory to individuals, families and
communities against any infectious disease.
Vaccines are cheap, cost – effective , easily
administered and adaptable to mass vaccination.
Vaccines are safe, thoroughly tested and monitored.
Vaccines stimulate both cell mediated and humoral
Viral diseases can be managed through vaccination.
Routes of vaccine administration
Deep subcutaneous or intramuscular – most
Oral route – Sabine polio vaccine, oral BCG
Intra-dermal route – BCG vaccine.
Scarification – small pox vaccine.
Intranasal route – live attenuated influenza
Live attenuated vaccines -1
The live vaccine usually contains an attenuated
non-pathogenic microorganism able to
replicate in the host and produce long term
Single dose is effective. No booster dose is
Live microorganism tends to survive longer in
the host and provide a wide range of immune
Live attenuated vaccines -2
Relatively safe. Most
Severe reactions are
viral vaccines belong to
Offers long term
induces, both antibody
as well as cell mediated
Only single dose is
Present the risk of
Present the risk of reverting
back to virulence and
Methods of attenuation
The aim of attenuation is to eliminate the
disease causing properties of the virus without
affecting its immunity-inducing properties.
Viruses are given several consecutive passages in an unrelated
host e.g. small pox virus in calf.
Given multiple passages in cell cultures e.g rabies virus human
Selecting less virulent strains e.g. cow pox virus for small pox.
Long term treatment of viruses with chemicals e.g. BCG in a
medium of bile.
Culturing viruses under unfavorable conditions-temperature
e.g. anthrax virus at40-50 0 C
Killed inactivated vaccines
The inactivation process is aimed at destroying
the pathogenicity of the microorganism while
retaining its immunogenicity.
Usually the pathogenic viruses are chemically
inactivated. E.g. polio vaccine, rabies vaccine.
Killed vaccines induce higher antibody titers
but not effective as live vaccines.
Killed vaccines are safe with respect to residual
Since antibody titers diminish with time,
repeated vaccinations are required.
The toxins of microorganisms are treated with formalin
and incubated at 37 0C for 3- 4 weeks.
The denatured toxin is called a ‘toxoid’.
Toxoids often induce low levels of immune response
and are often administered with an adjuvant.
Toxoid vaccines often require a booster every ten
Toxoids e.g. the diphtheria and tetanus vaccines are
usually combined with pertussis vaccine as DPT
When more than one vaccine is administered
together it is called ‘conjugated vaccine.
Biotechnology and genetic engineering
techniques have been used to produce
To create a subunit vaccine, researchers
isolate the genes which code for appropriate
subunits from the genome of the infectious
agent. This genetic material is placed into
bacteria or yeast host cells which then
produce large quantities of subunit molecules
by transcribing and translating the inserted
foreign DNA. These subunit molecules are
isolated, purified and used as a vaccine.
e.g. Hepatitis B vaccine
With DNA vaccines, the individual is not injected with
the antigen but with DNA encoding the antigen.
The DNA is incorporated in a plasmid containing DNA
sequences encoding one or more protein antigens.
DNA sequences are incorporated with a promoter that
will enable the DNA to be efficiently transcribed in the
The DNA vaccine can then be injected into a muscle
just as conventional vaccines.
DNA vaccines elicit cell-mediated and antibodymediated immune responses.
DNA vaccines has been developed against
tuberculosis, SARS, smallpox, and other intracellular
Properties of an ideal vaccine
1. Should provide long lasting immunity.
2. Should induce both humoral and cell
3. Should not induce autoimmunity or
4. Should be inexpensive to produce, easy to
store and administer.
5. Should be safe and effective.
The word adjuvant is derived from the Latin
word ‘adjuvare’ meaning ‘to help’.
Certain substances, when administered
simultaneously with a specific antigen, will
enhance the immune response to that antigen.
Such compounds are routinely included in
inactivated or purified antigen vaccines.
Adjuvants in common use:
1. Aluminium salts
First safe and effective compound to be used in human
vaccines. It promotes a good antibody response, but poor cell
2. Liposomes and Immunostimulating complexes (ISCOMS)
3. Complete Freunds adjuvant is an emulsion of
Mycobacteria, oil and water
4. Incomplete Freund's adjuvant as above, but without
5. Muramyl di-peptide
Derived from Mycobacterial cell wall.
IL-2, IL-12 and Interferon-gamma.
Mode of action of adjuvants
By trapping antigen in the tissues, thus allowing
maximal exposure to dendritic cells and specific
T and B lymphocytes.
By activating antigen-presenting cells to secrete
cytokines that enhance the recruitment of
antigen-specific T and B cells to the site of
Two types of vaccines are available for measles.
Mumps Measles Rubella vaccine, live (MMR-II)
Mumps Measles Rubella and varicella virus
MMR vaccine is a live attenuated viral vaccine
used to induce immunity against measles, mumps
The vaccine is administered to all children in the
second year of life.
A killed mumps virus vaccine developed in
1948 and used in the United States from 19501978.
Live attenuated virus developed in the 1960's.
MMR vaccine is an immunization vaccine
against measles, mumps and rubella(also called
German measles). All three diseases are highly
MMR is a mixture of live attenuated viruses of
the three diseases. The MMR vaccine is
administered to children by a subcutaneous
Live attenuated virus.
Rubella causes a mild febrile illness in children,
but if infection occurs during pregnancy, the
foetus may develop severe congenital
In the USA, the vaccine is administered to all
children in their second year of life .
Two polio vaccines are used to fight the disease
Inactivated polio virus vaccine (IPV) consists of
inactivated (dead) polio virus. It was developed by
Jonas Salk in 1952.
Oral polio vaccine (OPV) is a live attenuated polio virus.
This vaccine was developed by Albert Sabin in 1957.
OPV is adopted in most parts of the world.
The live viral vaccine induce life long immunity.
OPV is sensitive to storage under adverse conditions.
Hepatitis B vaccine
Two immunization vaccines are available for use:
a serum derived vaccine and a recombinant
Both contain purified preparations of the hepatitis
B surface protein.
The serum derived vaccine is prepared from
hepatitis B surface protein, purified from the serum
of hepatitis B carriers.
A second vaccine is produced by recombinant
Three doses are given to children at 6, 10, and 14
weeks of age.
Hepatitis A vaccine, HAV
HAV has been developed from formalin-
inactivated , Human fibroblast cell culture-derived
Hepatitis A is a serious liver disease caused by the
hepatitis A virus (HAV).
A combination vaccine containing inactivated
hepatitis A and recombinant hepatitis B vaccines
has been licensed since 1996 for use in children
aged one year or older in several countries.
The combination vaccine is given as a three-dose
series, using a 0, 1, 6 month schedule.
Yellow Fever vaccine
The vaccine consists of a live attenuated,
strain of the yellow fever virus called 17D.
Max Theiler developed the yellow fever
vaccine in 1937.
A single dose induces protective immunity
to travellers and booster doses, every 10
years, are recommended for residents in
Rabies is an acute, progressive encephalomyelitis
caused by neurotropic viruses in the family
The human diploid cell rabies vaccine (H.D.C.V.) was
started in 1967. Human diploid cell rabies vaccines
are made using the attenuated Pitman-Moore L503
strain of the virus.
Recombinant rabies vaccine (V-RG) was developed
in 1984 by inserting the glycoprotein gene from
rabies into a vaccinia virus.
The flu is a respiratory disease that is caused by an
Influenza Virus Vaccine is an inactivated influenza
virus propagated in embryonated chicken eggs.
It is an intramuscular injectable vaccine available in
The trivalent vaccine, which protects against three flu
The quadrivalent vaccine, which protects against four
flu virus strains
Varicella- Zoster virus vaccine
The vaccine is developed from a live
attenuated strain of varicella zoster virus.
It is used to protect individuals from chickenpox.
This vaccine is a shot given subcutaneously
(under the skin).
It is recommended for all children under 13 or
older who has never had chickenpox.
Two doses are administered 4 to 8 weeks apart.[
Live vector vaccines
A live vector vaccine is a vaccine that uses a
chemically weakened virus to transport pieces of
the virus in order to induce an immune response.
Viral vector vaccines are developed for major
infectious diseases like HIV, tuberculosis and
Vector vaccines are developed using
recombinant DNA technology.
Viral vectors elicit a strong humoral and cell
mediated responses and cause immunological
Cancer vaccines can be used as an active
immunotherapy and trigger the immune system to
attack cancer cells with one or more specific antigens.
Cancer vaccines are developed from proteins or
peptide antigens rather than whole tumor cells.
Two kinds of tumor cell vaccines : Autologous and
Autologous vaccine means ‘coming from the self’ =
killed tumor cells taken from the same person.
Allogenic vaccine means ‘coming from another’ =mix
of cells removed from several patients.
Problems in vaccine development
Many kinds of viruses may cause similar diseases. e.g.
common cold. A single vaccine may not prevent such
Diseases caused by RNA viruses may not be controlled
because of antigenic drift and shift.
Diseases present in large animal reservoirs may reinfect after elimination from the human population.
Integration of viral DNA into host chromosomes may
There is possibility of recombination and mutation of
attenuated viruses in vaccines.
Vaccines provide protective immunity and
immunological memory to individuals, families
and communities against any infectious
Vaccines are cheap, cost – effective , easily
administered and adaptable to mass
Viral diseases can be managed through
About the presenter
Dr. B. Victor is a highly experienced postgraduate
professor, retired from the reputed educational
institution - St. Xavier’ s College(Autonomous),
He was the dean of sciences, assistant controller of
examinations and coordinator several academic
He has more than 32 years of teaching and research
He has taught a diversity of courses and published 45
research articles in reputed national and international
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