Boosting Immunity

• What is immunity

  • If the same pathogen re-enters the body , the white blood cells respond more quickly to produce the correct antibodies 
  • This quick response prevents the person from getting ill and is called immunity
• In the UK we are vaccinated against a range of different diseases when we are young
• What is vaccination

  • Vaccination is where small quantities of dead or inactive forms of a pathogen are injected into the body 
  • Vaccination stimulates the white blood cells to produce antibodies and to develop immunity 
  • Because the pathogen is dead or inactive , it cannot lead to the disease in the patient
• Describe how a vaccination works

  • A weakened / dead strain of the pathogen is injected into the person’s body 
  • Antigens on the pathogen surface cause the white blood cell to produce specific antibodies against the weakened / dead strain of the pathogen 
  • At the same time the white blood cell divides by mitosis to produce lots of copies of itself 
  • The copies of the white blood cells remain in the bloodstream for a long time , and if the same pathogen enters the body later on , they can produce the correct antibodies quickly , to prevent infection

  
• Describe what this graph shows

  • This graph shows the level of the antibody after vaccination , and after the body is invaded by the real pathogen 
  • When the real pathogen invades, the antibody number rises very quickly and to a very high level 
  • This is due to the vaccination

  
• Why is it important that a large proportion of the population are vaccinated?

  • It is important that large groups of people are vaccinated against pathogens 
  • There are always some people that don’t get vaccinated (e.g. people who may be new to a country or missed their vaccination appointment)
  • If enough people are vaccinated , this protects unvaccinated people
  • This is because if enough people are immune to the pathogen , they cannot pass the pathogen onto unvaccinated people , and so the pathogen cannot spread very easily 
  • Scientists call this herd immunity