General Health and Immunity

What is Immunity?  Immunity is the ability to resist or to recover from an infection or disease.  Your immune system protects your body and keeps you from getting sick.

Words to know:  Pathogen: a disease-causing agent.  Antigen: a substance that triggers an immune response.

The Second Line of Defense  White blood cells: a type of cell in the blood that destroys bacteria, viruses, and toxic proteins and helps the body develop immunities.  T-Cells: attack and kill infected cells  B-Cells: label invaders for later destruction by white blood cells.  Memory Cells: remember disease causing cells so they can be recognized at a later date and increase immune response.

Active Immunity  Naturally acquired active immunity occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response.  Artificially acquired active immunity can be induced by a vaccine, a substance that contains the antigen.  A vaccine stimulates a primary response against the antigen without causing symptoms of the disease

How long does active immunity last?  It depends on the disease.  Some disease-causing bacteria evolve into new forms that our bodies don’t recognize, requiring annual boosters, like the flu shot.  Booster shot – An additional dose of a vaccine used to “boost” immune response.  Others last for a lifetime!

Passive Immunity  Artificially acquired passive immunity is a short-term immunization by the injection of antibodies that are not produced by the recipient's cells.  Naturally acquired passive immunity occurs during pregnancy, in which certain antibodies are passed from the maternal into the fetal bloodstream.  Tolerance for foreign antigens can be induced experimentally by creating conditions of high-zone tolerance (injecting large amounts of a foreign antigen into the host organism) or low-zone tolerance (injecting small amounts of foreign antigen over long periods of time.)

How do you become immune?  New particles take longer to identify, and a person remains ill until a new antibody can be crafted.  Old particles are quickly recognized, and a person may never become ill from that invader again.  This person is now immune!

Immune Disorders  Allergies Immune system mistakenly recognizes a harmless antigen as a serious threat. Immune system mistakenly recognizes a harmless antigen as a serious threat. Launches an immune response which causes histamines to be released. Launches an immune response which causes histamines to be released. Histamine cause swelling, redness, increased mucus production, runny nose, itchy eyes, and nasal congestion. Histamine cause swelling, redness, increased mucus production, runny nose, itchy eyes, and nasal congestion. Anti-histamines block effects of allergic reactions and bring relief to allergy sufferers. Anti-histamines block effects of allergic reactions and bring relief to allergy sufferers.