vaccines

• Vaccinations involves injecting very

  small quantities of dead or inactive pathogens into the body.
• • Your white blood cells will notice the pathogen and begin to produce antibodies.
  • Since the pathogen is dead/inactive it wont multiply during this time and you wont get sick.
  • If the same pathogen then re-enters the body the white blood  cells respond quickly to produce the correct antibodies, preventing infection. 
• Edward Jenner is the founder of vaccinations.
• How Vaccines Work:

  1. A small amount of dead or inactive pathogen is injected into the body.
  2. The pathogen has an antigen on its surface.
  3. White blood cells detect the antigen as a foreign body.
  4. White blood cells produce antibodies which lock onto the antigen destroying it.
  5. Memory white blood cells are produced.
  6. If the pathogen re-enters the body, the antibodies are mass produced very quickly, preventing re-infection.
• When your immune system encounters a new pathogen for the first time, it takes some time for it to develop the new antibodies.

  If the same type of pathogen enters the body again, your immune system recognizes it and the lymphocytes immediately start producing lots of the correct antibody/antitoxin.

  The person is now immune to that disease. 
• • Herd immunity- this involves a high percentage of a population being immune to a disease (due to vaccinations).
  • The disease cannot be passed on because it cannot find a new host and consequently dies.
  • If a high percentage of the population is immunised, the spread of a pathogen can be greatly reduced.