Vaccines and Antibiotics

• Why do we only get some diseases once?

  Immunity
• What is immunity?


  The ability of an organism to resist or defend against harmful pathogens or foreign substances.
• How do we become immune to certain diseases?

  Antibody -> Memory Cell -> Recognise antigen -> Immune
• How do vaccinations allow us to become immune?

  1. A vaccine is a weakened form of a disease (either killed or a similar but less virulent strain)
  2. The vaccine is injected into the body
  3. This triggers an immune response as each microorganism have the antigens to induce an immune response.
  4. Antibodies are produced that match the microorganisms antigens and attach to the antigens - neutralises the disease.
  5. Special WBCs are created called memory cells so when the real disease enters the body the immune system is then able to combat the disease immediately as it recognises the antigens
• Do vaccines work for all diseases?

  No. Vaccines are made to combat only viral and bacterial diseases.
• Facts about Measles

  • Spreads Easily
  • Can be fatal
  • Can leave people severly disabled
  • Vaccinated child is much less likely to develop measles
  • 1/100 vaccinated still get measles
  • Harmful effects of vaccines are rare and mild
  • Each vaccination costs the NHS a few pounds
• Testing Antibiotics

  
• Antibiotics are made naturally by bacteria and fungi to destroy other microorganisms
• Penicillin is made from fungi and is used to treat bacterial infections