Immunity

-Each cell has unique proteins on its surface called antigens. The antigens on the microorganisms which get into your body are different to the ones on you own cellsand your immune system recognises that they are different 

- Your white blood cells then make antibodies to attack the antigens, this destroys the pathogens

-Your white blood cells remember the right antibody needed to tackle a particular pathogen. If you meet that pathogen again, they can make the same antibody very quickly, so you become immune to that disease

-The first time you meet a new pathogen you get ill. That's because there is a delay while your body sorts out the right antibody needed. 

-Some pathogens can kill you, you can be protected from these diseases by immunisation/vaccination

-Immunisation involves giving you a vaccine, which is usually made up of a dead or weakened pathogen form of the disease causing microorganism

-It works by triggering your natural immune response to invading pathogens 

-A small amount of dead or inactive pathogen is introduced into your body. This gives your white blood cells the chance to develop the right antiboides against the pathogen without you getting ill

-Then if you meet the live pathogen, your white blood cells can repond rapidly. They can make the right antibodies just as if you already had that disease 

-We use vaccines to protect us against both bacterial disease and viral disease