Immunization.
Current Trends
2007
Dr.T.V.Rao MD
Immunization = Vaccination
What is a Vaccine
A vaccine is a substance that is
introduced into the body to prevent
Infection or a certain Pathogen
Can be used in bacterial, Viral,
Parasitic Infections.
History Guides
the Future
Edward Jenner Vaccinating
Beginning of Vaccination.
Vaccination ( Latin ;
Vacca- Cow )
Edward Jenner used
the term Vaccination
Cow pox virus
provided immunity in
prevention of Small
pox
Scientific Era of Vaccination.
Louis Pasteur adopts the
principles of Vaccination
For his scientific work.
Vaccination for prevention
of Rabies creates
awareness on
Immunization with
scientific fundamentals
Major Principles and
Methods of
Vaccination
Biological events guide the
Vaccination
Major content of Vaccines
1.
2.
3.
4.
5.
Toxoids
Inactivated vaccines.
Attenuated vaccines
Subunit vaccines
Hyper immune globulins.
What we have achieved with
Vaccination
Cost effective method in controlling the
infectious diseases.
 Small pox - Eradicated.
 Immunization prevents many diseases
 We have created Herd immunity in
commonly prevalent diseases.

Eradication of Small Pox
WHO efforts with
various Governmental
and Social
Organizations have
changed History of
Medicine
Principles of
Immunization
Development of Immunology has
foundations on Vaccines
Different protocols to Immunization
Passive Immunization
Active Immunization.
Passive Immunization

Passive immunization
Artificially created by passive method
Can be created at short notice,
Effective for limited periods,
Antibodies are created in various sources from animals to
humans
Can be Antiviral ,Antibacterial,
Source can be Animals, or Humans
Human source will be effective for 3-6 months.
Animals ( Heterologus ) effective for few weeks,
Passive Immunization
Diphtheria antitoxin - Horse- Equine Diptheriae
antitoxin.
Botulism - Antitoxin
Tetanus – Antitoxin. – Equine
Human Tetanus Immunoglobulin,
Pooled Immunoglobulins
Human Normal Immunoglobulin
Used for short term prophylaxis,
Eg Hepatitis A Immunoglobulin,
Passive Immunization
Highly Successful
Saves in Acute Infections
Diphtheria Antitoxin
Tetanus Antitoxin
Rabies Hyper immune Globulins( HRIG )
Varicella Zoster Hyper Immune Globulins
(HZIG)
Active
Immunization.
Most Ideal, Cost effective, method to
prevent communicable Diseases.
Active Immunization with Toxoids
Types 1
Toxoids - Single Toxin Modified
Preserves Antigenicity,
Loses its Toxicity.
Eg
1 Tetanus Toxoid
2 Diphtheria Toxoid

Active Immunization
Inactivated / Killed Vaccines,
Microbes are killed
Eg 1 Pertusis , (Whooping cough )
2 Influenza ( Flu)
3 Salk - Killed vaccine for
(Poliomyelitis) ,
Active Immunization
Attenuated Live vaccine
Inactivation destroys pathogen city,
Protective immunity is retained
Contains living organisms with reduced
virulance,
1 Live polio vaccines –Sabins,
2 Yellow fever vaccine 17D strain.
Different schedules
of Vaccination
May vary from Nation to Nation
Depends on Geographic,
Economic and prevalence of
Specific Diseases
Herd Immunity
Definition – When most of the People in a
community are immune to particular
infection-Natural transmission is inhibited.
 Herd Immunity works in infections
transmitted from person to person only.

The Mass oral polio vaccine creates a
Herd Immunity and protects the Society.
Immunization
Schedules
Depend on
Need,
Efficacy,
Safety,
Ease of administration,
Vaccines which
Changed the
History of Medicine
Vaccination for Polio, Tetanus
Diphtheria, Pertusis. Rabies
Universally accepted
Vaccination for Diphtheria,
Tetanus and Pertusis
Triple Antigen ( DTP )
 Contains Toxoids of Diphtheria and
Tetanus
 Pertusis component Contains whole Cell
preparation from Bordetella pertusis.

Three Doses given at the interval of 4-6
weeks
 Boosters at Later date

Vaccination for
Poliomyelitis
A great break through in Vaccine
Research
Millions saved from disabling Polio
Pioneers in Prevention of
Poliomyelitis
Vaccination in
Poliomyelitis

Vaccination for Poliomyelitis, can be oral or inject able.
Sabins – Mixture of 3 types poliovirus1,2,3
Live attenuated vaccine, A oral vaccine colonizes the gut produces
the local immunity and antibody mediated immunity protects ,
Rarely hazardous,

Salk – vaccine a killed vaccine not used in routine immunization
schedules. India


Sabin’s live polio vaccine is economical for mass vaccination in
populous countries
Component of Mass Pulse Polio Immunization programme
Commonly used vaccines,
MMR Vaccine
Used for the prevention of
Measles, Mumps, and Rubella.
Contains live attenuated strains,
Given at the age between 12-15 months,
But Measles vaccination is done early in India at 9 months.
Rubella
Rubella Vaccine is given separately to young women
Given to all sero negative women of child bearing age
Vaccination for Tuberculosis
BCG – Attenuated strains of Bovine
Tubercle Bacilli, ( Bacilli –ChalmetteGuerin)
 Efficacy ? But useful in the prevention of
Tuberculosis meningitis, and Leprosy
 Given on lateral aspect of arm, at the
deltoid insertion
 To be given intradermally,

Emerging Vaccines
Recently several persons
benefited.
Haemophilus influenza

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Type b serotype is capsulated and highly pathogenic,
Produces Meningitis,Bacteremias, Epiglottis's.
Encapsulated strain b is selected for vaccination.
Vaccine contains capsular polysaccharide linked to a
protein and protects against against type B strains.
In U K given along with DPT vaccine
When not given earlier A single dose for 1 – 4 years
children.
Elder children and Adults do not need unless
immunosupressed.
Meningococcal Vaccine
Men C Vaccine
The component of the vaccine is
Meningococcal C antigen,
 The polysaccharide component is linked to
protein carrier,
 In developed countries given at 2, 3, 4
months duration.
 Produces prolonged immune response.

Vaccination in Hepatitis A
Virus Infection
A formaldehyde inactivated vaccine
prepared from HAV grown in Diploid cells
A vaccination is effective for 10 years
Advised mainly in persons entering
endemic areas with HAV Infection.
Bio-Engineering
creates Vaccine
Hepatitis B Vaccine
Molecular Biology and Genetic
Engineering contributed for
HBV Vaccine.
Vaccination for Hepatitis B
Infection.
Hepatitis B Vaccine
 Bio Engineered vaccine,

0 -
1
- 6 months ( Dosage )
Deltoid region
 90% successful
 Universal Immunization – an ideal goal in
prevention of Hepatitis B infections.

Combined Vaccination for
Hepatitis A and B Infections.
Now a combined vaccine is available for
prevention of Hepatitis A and B
Available as
TWINRIX ( GSK )
Vaccination for Typhoid



Oral – Live ( Typhoral )
Stable mutant of S.typhi
Strain Ty2 ( Lacking enzyme UDP –Galactose 4
Epimerase).

Injectable vaccine ( Ty vi ) contains
Purified Vi polysaccharide Antigen
Efficacy lasts for 3 years
Needed for people traveling to Endemic areas
Other Vaccines
Pneumococcal vaccine
A polyvalent polysaccharide containing capsular antigen
with 23 Sero types
 Gives 80 -90 % protection
 Used in
Dysfunctional spleen
Sickle cell diseases,
Chronic diseases of Liver, lungs, heart,
Renal failure.
HIV infection
Effective in > 2 years old children,
Vaccine for Varicella
zoster
OKA strain, A live attenuated strain,
 Single dose for children ( 1-12 years
children)
 Not to be given in Immune suppressed /
HIV patients.

Vaccine for Influenza(virus )
Always use new vaccines with prevailing
strains,
 Now recombinant vaccines are available.
 Made in embroyonated eggs.

New Vaccines
Developed or on Trails
Vaccines for Rota Virus
Rota Rix ( GSK )
Introduced in Brazil, Elsalvador, Mexico,
Panama and Venezuela
Under Phase III trails in Africa, and Malawi
Rota Teq ( MEREK)
Introduced in Nicaragua
Newer Pneumococcal Vaccine
A Seven Valent conjugate vaccine
(Prevenar )
Effective against 7 strains prevalent in
certain geographic locations
Effective in 83 % HIV uninfected.
Effective in 65 % of HIV infected.
Human Papilloma Virus
Vaccine
Gardasil ( HPV vaccine ) developed by
Merck.
Effective against 4 common serotypes
( includes prominent serotypes 16 and 18
causing Cancer cervix ).
Adolescents and preadolescents considered
for vaccination.
Newer Meningococcal
Meningitis A Vaccine ( Men A )
Effective in Meningococcal Diseases
Phase I trails in India
Phase II trails , Mali, and Gambia
Phase III trails in Ethiopia /Senegal
Influenza
Current Vaccine
In view of changing strains the
antigens configuration for Influenza need
a new model vaccine every year /
frequently
Currently CSL Biotherapies vaccine is
licensed on 28th Sept 2007 for current
use.
Need for Vaccines in
HIV/AIDS
Why Vaccines are Difficult to
Development in AIDS
H I V infection is produced by most
complex virus ever identified and it is extremely
good at evading any Immune Mediated strategy
detected against.
H I V is Genetically diverse.
New forms ( clades ) are emerging all through
infection,
Vaccine Options
1 Live attenuated or whole killed HIV virus
Failed due to safety fears, Trails stopped.
2 Sub Unit vaccines ( gp 20 model )
Failed in Major trails.
3 DNA vaccines
Isolated HIV genes used to stimulate
cell mediated Immunity.
Vaccine Options ( Contd )
4 Recombinant Vaccine - Isolated genes
delivered through another viral vector,
Most trials use this method
Vaccine Options
5 Combination Vaccines.
Multiples trails are in progress
with combination of Designs, strategies,
And
Immunogens which can produce a
broader more powerful, and more durable
immune response.
The Quest for the
AIDS vaccine
continues
Various National and International
Organization are committed for
development of a effective Vaccine
Present HIV Vaccination Trails
Vaccination for
People at special risk
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Anthrax
Cholera
Hepatitis A
Hepatitis B
Influenza
Japanese B
encephalitis
Meningococcal
Infection
Plague
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Pneumococcal
infection
Q fever,
Rabies
Tick borne
encephalitis.
Typhoid
Typhus
Varicella Zoster
Yellow fever.
Contraindication to
Vaccination
I
In spite of great success with
many vaccines, yet a caution and
wisdom are essential
Contra -indications to
Vaccination
Do not give vaccines to acutely ill patients.
 Avoid giving live vaccines to pregnant
women
 Avoid all types of vaccines in the first
Trimester of pregnancy,
 Do not give live vaccines to
immunosupressed patients and patients
suffering with RES malignancies,

Contraindication ( Cont )
In spite of Immune suppression in HIV
infected, we can still give MMR and Oral
polio drops ( But Salk killed vaccine is
safe).
 In HIV patients do not give BCG vaccine

What is an ideal vaccine.
Promotes effective immunity.
 Controls lifelong protection.
 Safe, do not carry side effects.
 Stable, cheap,
 Acceptance by public.

Yet there is No Ideal Vaccine.
Care in Vaccination
Some subjects may develop acute
anaphylaxis with vaccination,
 Be prepared to resuscitate the individuals,

Unresolved problems
Nothing is perfect
 No Vaccine is totally Protective
 Influenza – Needs very frequent updating
 Cholera vaccine –Little effective in reality

WHO Initiatives
On Vaccine Strategies and
Development
WHO
Supports the Research of various Biological
Organizations which produce the Newer
Vaccines
Helps the Implementation various
programmers related to Vaccines
Vaccine Research
Now major research is focused on finding the
safe and Socially acceptable vaccines
Refer for current knowledge on Vaccines.
VACCINE - is a International peer-reviewed
journal of Vaccination Research
Indexed in Medline pISSN: 0264-410X
Science Hopes a Vaccine for
every Disease
Vaccination created HOPE in
Humanity
Created for awareness
among Medical and
Health care workers in
Developing world.
Dr.T.V.Rao MD
tvraodoctor2000@yahoo.co.in