About Immunity

Immunity is your body’s ability to recognize germs to prevent them from causing illness. The immune system’s job is to help identify and eliminate dangerous germs that enter the body before they can cause disease or damage. The ability of a cell to react immunologically in the presence of an antigen.

Our immune system protects us and helps fight off disease. Microorganisms, small microscopic organisms, and viruses are everywhere. Many microbes and viruses can cause disease and are termed pathogens. With all these pathogens around, our immune system gives us different types of immunity to protect us from disease. 

A weakened immune system, therefore, leaves your body vulnerable to disease. Many things can weaken the immune system such as chronic stress, a poor diet, lack of sleep, long-haul flights, heavy exercise, certain medications such as the steroids, and viruses.

There are two types of immunity: innate also called natural or inherited and adaptive.

Ab

Innate or Natural Immunity

Innate immunity is the immune system that is present when you are born. It is your body’s first line of defense against germs. It includes physical barriers, such as skin and mucous membranes and special cells and proteins that can recognize and kill germs. The problem with these special cells and proteins is that they can kill a germ, but once the germ is dead, the innate immune system forgets it. It does not communicate any information about the germ to the rest of the body. Without this information, the body cannot prepare itself to fight this germ if it should reinfect the body.

Adaptive Immunity

Adaptive immunity is protection that your body builds when it meets and remembers antigens, which is another name for germs and other foreign substances in the body. When your body recognizes antigens, it produces antibodies to fight the antigens. It takes about 14 days for your body to make antibodies. More importantly, the body memorizes this fight so that if it meets the same antigen again, it can recognize and attack more quickly.

There are two types of adaptive immunity: active and passive.

  • Active Immunity – antibodies that develop in a person’s own immune system after the body is exposed to an antigen through a disease or when you get an immunization (i.e. a flu shot). This type of immunity lasts for a long time.
  • Passive Immunity – antibodies given to a person to prevent disease or to treat disease after the body is exposed to an antigen. Passive immunity is given from mother to child through the placenta before birth, and through breast milk after birth. It can also be given medically through blood products that contain antibodies, such as immune globulin. This type of immunity is fast acting but lasts only a few weeks or months.