Vaccination

• Vaccination

  Introducing small quantities of dead or inactive forms of pathogen into the body
• Vaccination

  • The pathogen is dead or inactive, so it cannot lead to the disease in the patient
  • White blood cells are stimulated to produce antibodies against the dead or inactive pathogen
  • White blood cells divide by mitosis to produce lots of copies of themselves
  • These copies of white blood cells can stay in the blood for decades
  • If the same pathogen enters the body even years later, the white blood cells can produce the correct antibodies quickly, preventing infection
• Vaccination

  Directly protects us from infection by pathogens
• Antibody level

  Increases very quickly to a very high level when the real pathogen invades the body, due to the vaccination
• Herd immunity


  • When a very large number of people are vaccinated, it also protects unvaccinated people because the pathogen cannot spread to them
• Vaccination can prevent illness in an individual
• Vaccination can prevent the spread of pathogens in a population