Active immunization

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					Active immunization

   Immunology and microbiology
Outline of the lesson

   Immunization
   vaccination
What is an immunization?
   Any process that develops resistance to a specific
   The production of immunity in an individual by
    artificial means.
   the creation of immunity usually against a particular
   especially : treatment (as by vaccination) of an
    organism for the purpose of making it immune to a
    particular pathogen
Active immunization (vaccination)

   Involves the introduction of, either orally or by
    injection (inoculation), of specially treated
    bacteria, viruses or their toxins to stimulate the
    production of antibodies.
Active immunization……

   Active immunization is achieved by injecting( or
    administering orally) small amount of antigen, called the
    vaccine into the body of an individual.

   The process is called vaccination.
   If the whole organism is used as the vaccine, it is first
    made safe by being killed or attenuated.

   The antigen stimulates the body to manufacture
    antibodies against the antigen.

   Often a second, booster injection is given and this
    stimulates a much quicker production of antibody which
    is longer lasting and

   which protects the individual from the disease for a
    considerable time.
Types of vaccines used

1.   Toxoids

2. Killed organisms

3. Live vaccines ( attenuated organisms)

   Toxins produced by tetanus and diphtheria bacteria are
    detoxified with formaldehyde, yet their antigen properties

   Therefore, vaccination with toxoids will stimulate
    antibody production without producing symptoms of the
Killed organism.

   Some dead viruses and bacteria are able to provoke a
    normal antibody response and are used for immunization

   Example: Flu vaccine which contains dead flu virus.
Live vaccines( attenuated organism)
   Attenuated organism may be a mutant variety
    with the same antigen but lacking the ability to
    cause disease.

   Attenuated vaccine for the bacterial disease
    tuberculosis (TB), and for measles, mumps,
    rubella and polio are in general use.
Name of the disease   Vaccine
Influenza             Killed virus: must be of right strain
Mumps                 Living attenuated virus
Measles               Living attenuated virus
Poliomyelitis         Living attenuated virus given orally
Diptheria             Toxoids
Tubercuolosis         living attenuated bacteria
Whooping cough        Killed bacteria
Tetanus               Toxoids
Cholera               Killed bacteria
Typhoid fever         Polysaccharide extract from the
                      bacterial capsule.

   BCG- tuberculosis

   OPV- Poliomyelitis

   DPT- Diphtheria, whooping cough and tetanus.
Passive immunization

   Is induced by the injection of preformed antibodies.
What are antibiotics?

   Chemotherapeutic agent usually obtained from living

   Metabolic product of one organism that in minute
    quantity inhibits the growth of other microorganism.

   antagonism.
   Wakshman 1945, chemical substances of microbial
    origin which in small amounts exert antimicrobial

   In 1929 Alexander Fleming, on agar plate inoculated
    S. aureus, became contaminated with a mold that
    mold appeared surrounded by a clear zone, indicating
    inhibition of bacterial growth or lysis of the bacteria.
   Mold was identified as a Penicillium species.
   Antibiotic as penicillin.
                Common antibiotics

   includes penicillin, ampicillin,    cephalosporin,
    bacitracin, streptomycin and etc.
   They are used to treat various infections but tend
    to weaken the body’s natural defense mechanisms
    and can cause allergies.

   Overuse of antibiotics can leads to the
    development of resistant strains of
Characteristics of antibiotics

   Broad spectrum
   Prevent development of resistant form of the
   Should not produce side effects to the host.
   Should not eliminate the normal flora of the body.
How does antibiotic work?

   Inhibits cell wall formation
   Disrupts cell membrane
   Inhibits nucleic acid synthesis.
   Inhibit protein synthesis.
   Inhibits specific enzyme system.

   What are the antimicrobial action of different
    kinds of antibiotics?

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