Transcript Vaccination

Vaccination
active
natural
passive
adaptive
active
immunity
artificial
innate
passive
NATURALLY ACQUIRED IMMUNITY
• Active:
• Acquired through contact with
microorganisms (infection).
• Provides long term protection.
• Passive:
• Antibodies pass from mother to fetus
across placenta or in breast milk (IgG)
• Provides immediate short term protection
(few months)
ARTIFICIALLY ACQUIRED IMMUNITY
• Active:
• Antigens introduced through vaccination.
• Provides long term protection.
• Passive:
• Induced by the transfer of antibodies
• Referred to as: Immune serum
globulins(ISG), immune globulins (IG) or
gamma globulins
• Provides immediate short term protection
It was recognized long ago that
individuals who survived smallpox,
plague, and cholera rarely contracted the
disease again.
Vaccine:
Is a nonpathogenic immunogen that, when
inoculated into a host, induces protective
immunity against a specific pathogen.
A vaccine is antigenic but not
pathogenic.
• The terms vaccine and vaccination are
derived from vaccinia virus (smallpox
of the cow) developed by Edward
Jenner in 1798
• Rabies vaccine (developed by Louis
Pasteur in 1880).
Properties of Vaccines:
 Induce effective protection without
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significant danger of disease or severe side
effects.
Induce long-standing protection .
Must be able to stimulate cellular and
Humoral (Neutralizing Abs) immunity
against specific pathogen. Neutralizing
antibodies to minimize reinfection.
Inexpensive, and easy to produce.
Stable for storage, transport, and use
N
Types of Vaccines:
Active vaccine:
Microbes, or microbial antigens (capsular
proteins, toxins,…..) administrated to
produce humoral and\or cellular immune
response. long or permanent protection.
 Passive vaccine:
Protection transferred from another person
or animal. Temporary protection that
wanes with time.
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Control of vaccination procedure:
Factors that should be considered in
immunization procedure:
o Pathogenic dose.
o Form of vaccine.
o Site of administration.
o Individuals age.
o Individuals immunity.
Types of vaccines
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Live vaccines
Attenuated Vaccine
Killed \Inactivated Vaccines
Toxoid Vaccine
Subunit Vaccine
 Live vaccines
o Made from living infectious agents
without any amendment. not pathogenic
but immunogenic.
o Example: small pox vaccine, made of
live vaccinia cow-pox virus (not variola
virus) which gives cross immunity for
variola.
Attenuated Vaccine:
living microbes but have their virulence
weakened by heat or chemicals so the
immune response is similar to natural
infection.
 Should not be given to
immunocompromised.
 Example:
Viruses: oral Polio vaccine (Sabine),
Bacterial: BCG.
 Killed \Inactivated Vaccines:
dead or inactivated microbes by physical
or chemical treatment. Lost it’s virulence
but still immunogenic.
Example:
Viral: hepatitis A.
Bacterial: pertussis.
 Toxoid Vaccine:
Detoxified (inactivated) bacterial toxins by
formalin or heat .
Example: Diphtheria and Tetanus.
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 Subunit Vaccine:
Bacterial:
Capsular material: H.influenzae type b,
Pneumococci, Meningococci.
Viral:
capsid: surface antigen of Hepatitis B virus
 Recombinant Vaccine:
Genetically modified microbes with low
virulence (pathogenic genes are removed) .
HBV vaccine.
Adjuvants (aid):
-Bacterial
components or other
substances (chemical), suspended in oil
that administrated together with vaccines
to increase the effectiveness of
immunization.
Examples:
- The pertussis component of DTP
vaccine.
- Aluminum phosphate or hydroxide.
Conjugate Vaccine
o Conjugation is the process of linking
polysaccharide antigen to a protein
carrier in order to provoke stronger
immune response.
oThese vaccines are protective even in
children under two years of age.
oH.influenzae, N.meningitidis,
S.pneumoniae.
Conjugation
Conjugate vaccine
Bacteria
Carrier
protein
Polysaccharide
Polysaccharide
linked to carrier
protein
Immunization
schedule in KSA.
Examples of Vaccines
Polio:
attenuated; Sabine: administrated orally.
Inactivated; Salk: administrated
Intramuscular.
DTP (DTaP): Intramuscular.
-Diphtheria: toxoid
-Tetanus: toxoid.
-Pertussis: killed. acellular pertussis:
subunit
MMR: Live attenuated Subcutaneous.
-Measles. -Mumps. -Rubella.
Hepatitis B: Recombinant IM.
SUCCESFULL VACCINATION PROJECTS
SMALLPOX Vaccination WHO ( 1967 - 1977 )
Last naturally acquired case SOMALIA 1977
1978 last death
Global eradication 1979
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Afghanistan, Nigeria and Pakistan