Vaccination

Passive immunity:

  • Produced by the introduction of antibodies into indivdulas from an outside source
  • No direct contact with the pathogen or its antigen is necessary to induce immunity, it is acquired immediately
  • As the antibodies are not being produced by the individuals themselves, the antibodies are not replaced when they are broken down, no memory cells are formed ad so there is no lasting immunity

Active immunity:

  • Produced by stimulating the production of antibodies by the individuals' on immune system
  • Direct contact with the pathogen or its antigen is necessary
  • Immunity takes time to develop
  • It is generally long-lasting and has two types -

Natural active immunity -

  • Results from an individual becoming infected with a disease under normal circumstances
  • The body produces its own antibodies and may continue to do so for many years

Artificial active immunity -

  • Forms the basis of vaccination
  • It invloves inducing an immune response in an individual, without them suffering from the symptoms of the disease

                   Natural                                 Artificial

Active        Contact with pathogen         Antegenic material

Passive     Breast milk, placenta            Antibodies

Features of a successful vaccination programme:

  • A suitable vaccine must be economically available in sufficient quantities to immunise most of the vulnerable population
  • There must be few side effects if

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