The immune system recognizes a foreign substance using lymphocytes, and in the initial contact with the germ, only a small amount of lymphocytes recognizes the danger. Because of this, the defense may take a while to get rid of the culprit. In some cases, the germs can multiply faster than the lymphocytes can recognize and defeat them, causing the person exposed to the germ to become very ill and sometimes die. Vaccinations are a way of exposing the immune system to germs in a controlled situation. This gives the immune system a chance to mount a defense against viruses and bacteria.
Vaccines are a mix of substances, including bacteria, which have been weakened or killed so that they cannot cause disease. This manner of exposure allows the body to increase the number of lymphocytes that can recognize and defeat the invader. When the body is again introduced to the germ under normal (not controlled) conditions, the defense will be much quicker, and the germs will be stopped before they can cause illness. Depending on the type of vaccine administered, boosters may or may not be required. Some vaccines offer a lifetime of immunity.
Babies and children have lower immunity and can easily come down with many illnesses and diseases. Before babies are born, they are protected in the womb by antibodies in the mother's blood. These antibodies are also present in breast milk and will provide some protection very early in life. The side effects of vaccinations are typically mild, normally no more than a low-grade fever and some soreness at the injection site. These can be relieved by giving an over-the-counter children's pain reliever. All babies and children should get the vaccinations required to protect them from illness and disease.
Tags: immune system, recognize defeat