Thursday, 30 May 2013

AS Biology F212: Vaccines

A vaccine is a preparation containing antigenic material (e.g. antigens)

Vaccination confers artificial active immunity. (Entry of antigenic material into the body stimulates an immune response, memory cells are produce)

Types of vaccination
  1. Live vaccine e.g. Smallpox
    The live vaccine - less harmful pathogen but with similar antigens and can still be induce active immunity
  2. Harmless vaccine e.g. measles, TB
    Harmless or attenuated version of the pathogen
  3. Dead vaccine e.g. Cholera vaccine
    the pathogen has been killed either by exposure to or chemicals
  4. Antigens e.g. hepatitis B
    Preparation of antigens from a pathogen
  5. Toxoid vaccine e.g. tetanus
    vaccine consists of harmless form of toxin produced by the pathogen

Herd vaccination
  • providing immunity to almost all of the population at risk
  • with enough people immune the disease cant spread
  • level of immunity needed varies depending on the disease (80-85% for small pox, 95% for measles)
Ring vaccination
  • used when a  new case s reported
  • vaccinate everyone in the immediate vicinity (house, village, or town)

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