Vaccination and immunisation.

1. VACCINATION AND IMMUNIZATION
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2. VACCINATION AND IMMUNIZATION
IMMUNISATION: This refers to the process where a person is made
resistant or immune to an infectious disease
VACCINATION: This refers to the process of stimulating the body’s own
immune system for protection against infectious diseases
VACCINE: A product which when introduced into the body produces
immunity from a disease. Can be administered by injection, mouth or
through the nasal route.
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3. CLASSES OF IMMUNITY
• Immunity to an infection can be acquired
- Passively: through the receipt of preformed antibodies or
- Actively: through an immune response following a deliberate or
accidental exposure to a microbe or their component parts
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4. Passive immunity (acquired)
• This form of immunity does not last long hence the name passive
• Humoral antibodies of the IgG subclasses pass across the placenta to
foetus
• This antibody will provide immunity (Passive) for the new born
against most diseases involving humoral immunity and those to which
the mother is immune
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5. Passive Immunity (acquired)
• IgA antibodies are also passed into the gut through the first breast
milk (colostrum)
• These antibodies provide protection against infections of the GIT
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6. ACTIVE IMMUNITY (acquired)
• This relates to the exposure of the immune system to antigens and
the subsequent response
• Such response might be related to
- an infection or
- Multiplication of an attenuated vaccine strain
- The introduction of non viable antigenic material into the body
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7. Active immunity (acquired)
• It is important to note that, the route of exposure of antigen will
determine the nature of subsequent immune response
- Thus vaccination by injection of vaccine (antigen) will lead to humoral
production of antibodies (IgG and IgM)
- Vaccination with the gut and respiratory tract will lead the production
of secretory antibodies (IgA and IgE) and also stimulate humoral
antibody production
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8. Vaccines
Vaccines are immunogens capable of stimulating the host immune
system, where deliberate exposure of the antigen results in the
production of memory B and T lymphocytes against specific targets
A patients is said to be adequately immunised when a second exposure
enables the individual to rapidly respond to the antigen with both the
humoral and cellular components.
The purpose of vaccination therefore is either to prevent or reduce
acute clinical manifestation of infection
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9. Characteristics of an ideal vaccine
• Able to mimic the immunological response as if an actual pathogenic
incursion
• Induce immune response as true infections
• Able to provide a continuous supply of antigens
• Immunological activation of both cellular and humoral response
- B lymphocyte expansion
- T lymphocyte expansion
- Elevation of antigen specific IgG
- Durable life long memory
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10. TYPES OF VACCINES
• Live vaccines
• Inactivated vaccines
• Purified macromolecules
• DNA vaccines
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11. Types of vaccines
Live vaccines
- attenuated vaccines (chemical, heat, irradiated)
- non- pathogenic mutant
- related non- pathogenic species
- recombinant live vaccines
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12. • These are produced from live infective microorganisms which are
associated with the disease and may produce subclinical infections
• They are produced by attenuating a pathogen either by heat, chemicals or
a combination of agents
• The attenuated organisms is able to proliferate and thus provide continual
supply of antigen for priming
• The organisms are however attenuated with respect to their
pathogenicity but retain their ability to infect
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LIVE ATTENUATED VACCINES

13. • Immunization with live vaccines have some advantages thus,
- Mimics the course of natural infection
- Exposure may be mediated through the natural route of
infection
- Continual antigen supply
DISADVANTAGES ???????
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14. Disadvantages include;
- Organisms may replicate in patient and may be transmitted to others.
This may be due to reduction in attenuation
- Immunological status of the patient might affect the course of action
of vaccine and side effects
- Organisms may revert back to pathogenic state if attenuation is not
properly done
Live, Attenuated vaccines
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15. INACTIVATED VACCINES
• Vaccines produced in this manner are unable to evoke natural infection
profile with respect to antigen release, hence must be administered on a
number of occasions to maintain immunity
• The specificity of the immune response may be initially low
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16. • These vaccines contain non-replicating organisms or cellular fractions
• They do not provide continues antigenic challenge hence
immunologic priming is not possible
• They are less effective as compared to attenuated vaccines
- Due to less immunogenicity (disruption of natural conformation of
antigen, antigen breakdown or interaction with cellular components)
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INACTIVATED VACCINES
killed vaccines

17. Killed vaccines
- Heat inactivation
- Irradiation
- Chemical
heat inactivation is generally unsatisfactory because of extensive protein
denaturation
Chemical inactivation with formaldehyde or other alkylating agents have
been successful.
Adjuvants (mostly made of Al compounds) are added improve the
immunogenicity and serve as emulsifying agents and my act as drug delivery
system
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INACTIVATED VACCINES

18. Fractionated proteins
Composed of only the immunogenic component of the antigen.
Disruption of the cellular structure is followed by isolation of the
cellular fraction.
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INACTIVATED VACCINES

19. Anti-idiotype
Vaccines have also been produced using antibody technology. Anti-
idiotype antibodies are secondary antibodies targeted against the
antigen binding fragment or the primary antibody that is specific for a
region on the antigen.
Anti-idiotype antibodies serve as the immunogen. Structurally, the
private anti-idiotype antibody resembles the original antigen and is
utilised as the antigen to produce the vaccine
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INACTIVATED VACCINES

20. Purified macromolecules as vaccines
• Bacterial polysaccharide capsules as vaccines
- Coating the capsule with antibodies and/ or complement greatly
increase the ability of macrophages and neutrophils to phagocytose
such pathogens.
- The limitations with this vaccine is the inability to activate helper T
cells. This results in little development of memory cells
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21. • Toxoids from bacterial toxins
Some bacteria produce exotoxins eg tetanus, diphtheria. These
exotoxins produce many of the disease symptoms that results from the
infection.
• Purifying the bacterial exotoxins and inactivating the toxin with
formaldehyde forms the toxoid.
• Vaccination with the toxoid induces anti-toxoid antibodies which are
capable of binding to the toxin and neutralizing its effects
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INACTIVATED VACCINES

22. • DNA VACCINES
READ ON THEM
ASSIGNMENT
FIND OUT EXAMPLES OF LIVE ATTENUATED VACCINES AND
INACTIVATED VACCINES
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23. VACCINATION AGAINST INFECTIOUS DISEASES
• In Ghana, childhood immunization against certain infectious diseases is
very critical since these diseases can have devastating effects on the health
of the child
• Diseases covered under childhood immunization in Ghana include;
- Measles caused by measles virus
- Whooping cough caused by Bordetella pertussis
- Tetanus caused by Clostridium tetani
- Diphtheria caused by Corynebacterium diphtheriae
- Poliomyelitis caused by Polio virus (type I, 2,3)
- Yellow fever caused by virus transmitted by Aedes aegypti
- Hepatitis B caused by HBV
- Haemophilus influenza type B infection
- Tuberculosis Mycobacterium tuberculosis 23

24. Caused by Polio virus
Has three immunological serotypes (I, 2, 3)
The infection is transmitted from faecal to oral routes
Vaccination is by administration of
- Live Oral Polio Vaccine (OPV) Sabin vaccine
- Inactivated Polio Vaccine (IPV) Salk vaccine
Poliomyelitis
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25. Measles
• Severe, acute, highly infectious disease
• Complications can occur leading to encephalitis
• Immunisation is by administration of MMR vaccine
• A lypholised preparation of live attenuated strains of measles, mumps
and rubella
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26. Tuberculosis
• Acquired by inhalation of M. tuberculosis or M. bovis
• Vaccination is by administration of a live vaccine (BCG) for protection
• Both humoral and cell mediated immunity is required for total
protection
• BCG (Bacille Calmette-Guerin) is derived from an attenuated M. bovis
strain
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27. • A sensitivity test is always conducted before the administration of BCG
• A Mantoux skin test is done to assess individual’s sensitivity to the
tuberculin antigen (PPD)- a purified protein derivative extracted from M.
tuberculin
• A positive test implies infection or past successful immunization
• A strong positive test implies active disease and should be referred
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Tuberculosis

28. Diphtheria, Tetanus and Pertussis
• Immunization against these infections is by the administration of
DTaP vaccine
• The vaccines are non- living hence can be given together
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29. Childhood immunization plan in Ghana
Age Vaccine dose
Birth BCG
Polio ‘O’
0.05ml intradermal
2 drops orally
6 weeks Five in one 1
Polio ‘1’
0.5ml IM
2 drops orally
10 weeks Five in one 2
Polio ‘2’
0.5ml
2 drops orally
14 weeks Five in one 3
Polio ‘3’
0.5ml
2 drops orally
9 months Measles 0.5ml deep SC or IM
9 months Yellow fever 0.5ml IM
Five in one vaccine : Diphtheria, Pertussis, Tetanus, Haemophilius influenza B and Hepatitis B 29

30. Storage of vaccines
• Vaccines should be stored and handled appropriately to ensure effectiveness
• This will ensure that immunization is adequately achieved
• Most vaccines are presented with adequate instructions for storage and handling
• All vaccines are to be stored in refrigerators as cold chain drugs (mostly within the
temperatures of 2 - 8 degrees Celsius)
• Information on the adequate temperature for a particular vaccine can be
obtained from product information
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