How does a vaccine "protect" your body from infection?
1 Answer
Vaccines use dead or weakened antigens to stimulate the body's immune system to produce antibodies against an infection with that antigen.
Explanation:
Very simply, vaccines imitate an infection, thus stimulating the body's immune system to produce antibodies that, in the eventuality of that particular infection, will act faster and better at containing the infection.
Most vaccines use attenuated (weakened) or inactivated (dead) antigens to produce this effect.
These antigens can either be the whole infectious agent - bacterium or virus - or a part of the infectious agent that is most antigenically reactive.
The purpose of attenuation or inactivation is to ensure that the vaccine does not cause the disease but merely stimulates the immune system to produce antibodies, usually with lasting memory cells, to prevent an actual infection from becoming serious.
It is these memory cells in the immune system that get triggered when an actual infection occurs, stimulating a massive immunological response to protect the body from that infection.
