The immune system is a complex collaboration of cells and proteins that protects the body against disease-causing germs. Its potent defense is orchestrated by the production of antibodies and lymphocytes capable of reacting with, and inactivating, the broad range of disease-causing agents that invade our bodies. Innate immunity, which includes a variety of physical barriers and soluble proteins that recognize and neutralize invading pathogens, is an integral component of this protective process.
Immunity is a process by which the immune system defends the body against substances that it sees as harmful or foreign, such as bacteria, viruses, fungi, chemicals, and cells that are damaged from things like cancer or sunburn. Your immune system attacks antigens by making a special class of proteins called antibodies. These antibodies attach to and weaken or destroy the antigens, as well as other cells that have been damaged by the same antigen.
Normally, after the immune system encounters a particular germ for the first time, it stores information about it in types of white blood cells called B and T cells. This provides the immune system with “memory” and means that if that same type of germ invades again, your body can respond more quickly and effectively to defeat it.
You can develop immunity naturally – or artificially – through infection or vaccination. The innate immune system is functional at birth but requires immunologic experience for optimal function. Innate immunity is short-lived and requires booster doses. Adaptive immunity, however, is able to last much longer. This is achieved through a natural process of infection or through immunization, and it allows the body to gain immunity to many diseases for life.