Vaccines and Antibodies in Medicine


HideShow resource information

Vaccines can protect individuals and populations a

  • While B cells divide to build up numbers in order to deal with the pathogen(eg. Primary response) you suffer from the disease.
  • Vaccination can help avoid this.
  • Vaccinations contain antigens --> make you body produce memory cells against the pathogen ( with out causing disease) 
  • This means you become immune with out getting any symptoms
  • They can reduce the occurrence of a disease. Even not vaccinated people will be less likely to catch the disease due to less people to catch it from. ( HERD IMMUNITY)
  • Vaccinations always contain pathogens- free, or attached to dead/ attenuated( weakend) pathogen.
  • Vaccinations can be taken via injection or orally. But if they are taken orally a disadvantage would be enzymes in the gut could break it down OR  molecules may be too large to be absorbed in to the blood.
  • Booster vaccines can be give later on to make sure memory cells are produced.
1 of 5

Antigenic Variation helps some pathogens evade the

  • Antigens on pathogens surface activate primary response
  • When infected a second time by the same pathogen you get a secondary response..
  • BUT some pathogens can change their surface anitigens ( antigenic variation)
  • Different antigens are formed due to changes in the genes of a pathogen
  • SO when you are infected for the second time, the memory cells from 1st infection wont recognise the different antigens
  • The immune system will have to start from scratch and carry out primary response again
  • You suffer symptoms again and feel ill as the primary response takes time to get rid of new infection
  • Antigenic variation makes it difficult to develop vaccines against some pathogens for the same reason
  • FOR EXAMPLE - HIV, S.pneumonia and influenza
2 of 5

Antigenic Variation and the Influenza Virus

  • Causes Flu
  • Protiens ( neuraminidase and haemagglutinin) on the surface of the influenza virus act as antigens --> triggering an immune response.
  • These antigens change frequently forming new strains of the virus.
  • Memory cells produced from the infection with one strain, will not recognise other strains with the other antigens,
  • So your immune system produces a primary response every time you are infected with a new strain
  • SO, you suffer from the flu more than once ( each time with a new strain)
3 of 5

Monoclonal Antibodies can be used to target specif

  • Monoclonal antibodies= produces from a single group of genetically identical b cells


  • Cancer cells have tumour markers- not found on normal body cells 
  • Monoclonal antibodies can be made to bind to these markers when they come into contact
  • you can attatch anti cancer drugs to the antibodies
  • So the drug will only accumilate where there are cancer cells- reduces side effects of drugs

EXAMPLE TWO - PREGNANCY TESTS ( they detect human chorionic gonadotropin (hCG) )

  • Antibodies  for hCG are attatched to a blue bead
  • When urine is applied to application area any hCG will bind to antibody - antigen-antibody complex
  • urine moves up the stick to test strip carrying the beads with it
  • strip contains hCG that are stuck in place ( immobilsed)
  • If there is hCG present test strip turns blue, if not it will pass through test area and not turn blue.
4 of 5

Ethical Issues surrounding vaccines and antibodies


  • All vaccines are tested on animals first
  • Animal based substances may be used to produce a vaccine
  • Testing on humans - volunteers put them selves at unnecassary risk ( eg contracting the disease)
  • Some people dont want to take the vaccine due to risks of side effects, but are still protected due to herd immunity - unfair
  • If there was an epidermic of a new disease, there would be a rush to receive it. Difficult decisions would have to be made about who would be 1st to receive it

Monoclonal Antibody therapy

  • Animals are used to produce the cells from with they are produced.
5 of 5


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Health, illness and disease resources »