Immunity refers to the natural defense mechanisms in the body that staves an infection, disease or attack by unnecessary biological intrusion. When a person is born, this innate immune system already exists and this forms a protection in the body from pathogens causing problems. The system automatically adapts to new diseases and forms an adaptive resistance against pathogens. This type of immunity surfaces after immunization or infection occurs and remains in the body for life.
There are two important types of adaptive resistance which can be further divided into artificially acquired immunity or the naturally acquired one. The immunity that is artificially acquired through vaccinations or some deliberate action is the first type and naturally acquired one refers to the second type which is acquired unconsciously by pathogens. These types are further divided into passive and active immunity depending on whether it is transferred passively or if it is induced in the host.
Active immunity is generated by the antigen in the host and can last a lifetime. The toxin or enzyme that is called antigen stimulates the body response to immunity and enhances the production of antibodies by the same immune system.
It is possible to develop passive immunity by activating the T-cells from immune hosts or acquiring antibodies. The information about various pathogens is received by the body and it uses its own defense mechanisms to deal with the problem. Passive immunity only lasts for a couple of months unlike active immunity.
Adaptive immunity is also referred to either as humoral immunity or cell mediated immunity and this is determined by the involvement of cells. Active humoral immunity relates to generation of one’s own antibodies while passive immunity relates to receiving antibodies from other people. Passive immunity refers to received T-cells from another person while your own T-cells are activated with cell mediated immunity.
Both humoral as well as cell-mediated aspects of immunity require some inputs from the innate system. Your body builds up T-cells and memory B-cells when pathogens activate the T-cells and B-cells. If the same pathogens are encountered, the body will fight them with innate vitamins as they use their cells for “memory recall”. The body thus faces all challenges with the immune system by using this adaptive and active immunity.
If your body is exposed to disease producing live pathogens, the naturally acquired active immunity comes into force to help the body develop the first immune response which leads to immunological memory. This is called natural immunity as it is not caused by deliberate exposure. If the system does not function properly the activity immunity formation gets disturbed.
Vaccination develops the artificially acquired type of active immunity. This is because vaccines contain antigens and a primary response against this antigen is first induced. Vaccines are not responsible for causing symptoms of any disease. Louis Pasteur, a pioneer in the field of vaccination was coming up with a method for enabling treatment of infectious agents for such infectious diseases to prevent them from causing major illnesses.