In general, immunity is the ability of human body to fight diseases with the help of pathogen. When it is needed, the organisms launch a rapid response to the immune system and prevent the illnesses from occurring. Such activations of human body could happen either naturally or artificially which in turn divide immunity systems into two categories natural and artificial. The first one operates without any interventions of the person. The artificial immunity activates only when antibodies are given to the person unnaturally, usually via injections. Both artificial and natural immunities could be active or passive (Bowman, 200. The latest one occurs when person is provided with antibodies derived from the other person (for example, the mother gives antibodies to the child). When the person is given injections of antibodies a short-time immunity appears, as no cell remembers what has actually happened. Long-term immunity could be gained through the active one. It occurs when the immune system is activated by the injection of already dead antigens, and the immune response starts as a result of memory contained in cells.
Numerous internal factors, including stress, have been long researched and are proved to cause the malfunction of the immune system of