Immune Health: Overview
The Immune System
The immune system is a large, interactive network of cells that protect against foreign bacteria, viruses, and fungi. It is broadly divided into innate and adaptive immunity, which are equally important for an adequate immune response to microbial pathogens and immunizations to help prevent and limit infectious disease1.
Innate immunity is present from birth, and consists of physical, chemical, and biological barriers including skin, stomach acid, and the microflora in the gastrointestinal tract, all of which help obstruct the entry of pathogens, as well as cells that trigger their destruction. Adaptive immunity, considered the second line of defense, is activated when pathogens gain entry into the body. It’s comprised of T-cells, B-cells, and antibodies that destroy specific pathogens. The adaptive immune system develops with time and is capable of remembering pathogens in the future2.