Immunisation And Autoimmunity

Immunisation

Introduction of the disease causing agent (substance or the pathogen) into the body in attenuated or detoxified form that makes body able to
develop antibodies against it.

Table : Important vaccines for babies and children

The antigenic property of toxin (or pathogen) remains intact. e.g. toxin for botulism, tetanus etc.
Edward Jenner first introduced the fluid from small pox sore of a milkmaid into scratched skin of a boy who showed resistance to the disease.
Louis Pasteur later developed vaccines against chicken cholera, rabies, anthrax etc.
Stepwise various doses of vaccines are given at particular intervals according to the type of disease. These doses evoke the primary, secondary and tertiary immune responses which gradually increase the level of antibodies in the body. After a long interval a booster dose is given  which regenerate sufficient amount of antibodies.

Autoimmunity

Sometimes antibodies are formed against own body substance which also affects the related organs. Variety of autoimmune disease are :

• Destruction of RBC by own antibodies.
• Myasthenia gravis : Antibodies are formed against the enzyme acetylcholinesterase hence acetylecholine is not removed from the muscle  causing its continued contraction and degeneration of its protein.
• Hashimoto disease : When thyroxine is secreted in less amount, antibodies are formed against it, this ultimately affects thyroid gland itself.
• Rheumatic fever : Neutrophils affect the tissue of joints and heart valves after exposure to streptococcal toxin.
• Glomerulonephritis : Immunity develops against basement membrane of glomeruli.
• Lupus erythematosus : Immunity develops against many different tissues of the body.

Immunodeficiency

• Severe Combined Immuno Deficiency (SCID) is an inborn defect. There is no formation of B and T-cells hence no survival is possible in  this case.
• AIDS - (Acquired immuno deficiency syndrome) Pandemic disease of late 20th century as a major blow to survival of human race. The HIV destroys our immune system by killing TH cell.