I was wondering what does your body do when you receive a vaccine?

Vaccination: Vaccination causes your body to initiate an immune response to the virus or bacteria in the vaccine, basically calling in the troops to better fight. Clonal proliferation of cells and antibodies specific to the vaccine will happen and you will have more and ready defenses if exposed to that particular virus or bacteria.

Go to work: A vaccine exposes your body to material meant to trigger antibody (fighter cells) that would have been created if you had the real disease. If you build enough antibodies, the disease cannot start in you after exposure because you have specialized fighters that kill it before it gets started.