16 Jan Natural Immunity Vs Acquired Immunity
Natural immunity also known as innate immunity or non-specific immunity is a mechanical barrier and the first line of defence against bad bacteria . It involves spontaneous and rapid immune response using molecules that are designed to know whether a dangerous invader is present, rather than long lasting protection. It is the protection provided by the skin, respiratory tract (lungs) and in the gut wall. For example, actions such as coughing and sneezing are the immune system’s way of expelling the virus or bacteria from the nose and throat . Tears clear the eyes of dust and other irritants, while diarrhoea and vomiting are mechanical methods for expelling unwanted germs from the gut.
Acquired immunity develops through exposure to specific germs and these are remembered by the body’s immune system . When the same bacteria enters the body again, the immune system remembers how to respond to them, such as with chickenpox . For example, once a child is exposed to chickenpox, the immune system will produce proteins called antibodies that will destroy the chickenpox virus . When your child is exposed to chickenpox again, the immune system is primed and knows how to fight the virus.
Antibodies are part of the immune system found in the bloodstream. They are large Y-shaped proteins that circulate in the blood and are recruited by the immune system to detect and destroy foreign invasion from bacteria and viruses.
Antibodies can attach themselves to the bacteria or virus at the top of the Y-shape and this inactivates or kills the germ. They also attract other immune system cells to destroy the invading germ.