Immune system

The immune system is the complex system in the body responsible for fighting disease. Its primary function is to identify foreign substances in the body (bacteria, viruses, fungi or parasites) and develop a defense against them. This defense is known as the immune response.

It involves white blood cells and the production of protein molecules called antibodies to eliminate foreign organisms that invade the body.[1]

## References[edit]

1. ↑ https://www.cdc.gov/vaccines/about/terms/glossary.htm#i