Immune System Cells and Immunity Definition - Active Passive and Acquired Immunity

Immune System Cells and Immunity Definition - Active Passive and Acquired Immunity-types of immunity. In biology, immunity is the balanced state of multicellular organisms having adequate biological defenses to fight infection, disease, or other unwanted biological invasion, while having adequate tolerance to avoid allergy, and autoimmune diseases. https://en.wikipedia.org/wiki/Immunity_(medical) Credits: Fuse School http://www.youtube.com/fuseschoo #immunity #activeimmunity #passiveimmunity