Definition, Meaning & Synonyms

antigen

noun

/ˈæn.tɪ.dʒən/

Definition

A substance that induces an immune response in the body, especially the production of antibodies.

Examples

Vaccines often contain antigens to help train the immune system.
The antigen on the surface of the virus helped scientists develop a targeted treatment.
Blood tests can detect the presence of specific antigens to diagnose infections.

Meaning

Antigens are typically proteins or polysaccharides found on the surface of pathogens like bacteria and viruses, or on cells, that trigger the immune system to recognize and respond to foreign invaders.