“Antibiotic” vs. “Antibody” vs. “Antigen”: What’s the difference? 

An antibioticis a medicine used to fight bacterial infections. It does not work against viruses. Antibodies are special proteins that the immune system produces in response to antigens. And antigens are substances that can stimulate the body’s production of antibodies.

Click here to read a full explanation of how these things work in your body to help you fight off disease.