Immunity, Vaccinations and Developing Drugs

Active and Passive Immunity

Active

Your immune system makes it's own antibodies after being stimulated by an antigen. There are two different types:

• Natural - immune after catching the disease 
• Artificial - immune after being given a vaccination containing a harmless dose of the antigen

Passive

Immunity you get from being given antibodies made by a different organism - immune system doesnt produce antibodies of its own. 

• Natural - a baby becomes immune due to antibodies recieved from mother through placenta and breast milk.
• Artificial - you become immune after being injected with antibodies from someone else e.g. tetanus. 

Vaccination

While your B lymphocytes are busy dividing to build up their numbers to deal with a pathogen, you suffer. Vaccines contain antigens that cause your body to produce memory cells against a particular pathogen, without it causing disease. This means you are immune without contracting any symptoms. The antigens may be free or attached to a dead or weakened pathogen. Vaccines can be injected or…