follows rigorous standards of quality and accountability. is accredited by URAC, for Health Content Provider (URAC's accreditation program is an independent audit to verify that A.D.A.M. For example, a person who has had chickenpox or has been immunized against chickenpox is immune from getting chickenpox again.Ī.D.A.M., Inc. In many cases, it will prevent you from getting sick. This allows your immune system to respond faster and more efficiently the next time you are exposed to the same antigen. Once B cells and T cells are formed, a few of those cells will multiply and provide 'memory' for your immune system. They also release chemicals, known as cytokines, which control the entire immune response.Īs lymphocytes develop, they normally learn to tell the difference between your own body tissues and substances that are not normally found in your body. T lymphocytes attack antigens directly and help control the immune response.Antibodies attach to a specific antigen and make it easier for the immune cells to destroy the antigen. B lymphocytes become cells that produce antibodies.Lymphocytes are a type of white blood cell. Some of these directly attack foreign substances in the body, and others work together to help the immune system cells. It also includes chemicals and proteins in the blood, such as antibodies, complement proteins, and interferon. The immune system includes certain types of white blood cells. Immune serum globulin (given for hepatitis exposure) and tetanus antitoxin are examples of passive immunization. It provides immediate protection against an antigen, but does not provide long-lasting protection. Passive immunization may also be due to injection of antiserum, which contains antibodies that are formed by another person or animal. These antibodies disappear between ages 6 and 12 months. Infants have passive immunity because they are born with antibodies that are transferred through the placenta from their mother. Passive immunity is due to antibodies that are produced in a body other than your own. Your immune system builds a defense against that specific antigen. If an antigen gets past these barriers, it is attacked and destroyed by other parts of the immune system.Īcquired immunity is immunity that develops with exposure to various antigens. Examples include the body's complement system and substances called interferon and interleukin-1 (which causes fever). Innate immunity also comes in a protein chemical form, called innate humoral immunity. Mucus, which traps bacteria and small particles.These barriers form the first line of defense in the immune response. Innate immunity involves barriers that keep harmful materials from entering your body. Innate, or nonspecific, immunity is the defense system with which you were born. Your immune system learns to see these antigens as normal and usually does not react against them.

These include a group of antigens called HLA antigens. Your body's cells have proteins that are antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens. Nonliving substances such as toxins, chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. The immune system protects the body from possibly harmful substances by recognizing and responding to antigens.

Antibody reactivity