Vaccination

• Vaccine - contains dead or weakened version of the pathogen
• It triggers an immune response to destroy the pathogen and creates memory cells. So if the pathogen re-enters the body it is recognised and phagocytes are made quickly which then destroy the pathogen
• Herd immunity - when a large proportion of a population is vaccinated, so that the disease cannot spread as easily
• Herd immunity protects people who are unable to get vaccinated e.g. older people, people with allergies or with an weakened immune system
• Advantages of vaccination:

  • They have eradicated many diseases and reduced the occurrence of many
  • Epidemics can be prevented through herd immunity
• Disadvantages of vaccination:

  • They aren't always effective in providing immunity
  • Bad reactions can occur in response to vaccines