2. The immune system is a complex network of specialized organs and cells protects the body from destruction by foreign agents and microbial pathogens , degrades and removes damaged or dead cells, and exerts a surveillance function to prevent the development and growth of malignant cells. The immune system is composed of immune cells and central and peripheral lymphoid structures. The immune cells move throughout the body, searching for and destroying foreign substances but avoiding cells regarded as self.
3. Natural immunity: It is not produced by the immune response. This type of immunity is present at birth and appears to be present in all members of a species. Acquired immunity: It develops after birth as a result of exposure to an antigen, thereby activating the immune response. Acquired immunity can be either active or passive, depending on whether the immune response took place in the host or a donor.
4. Differences of immune system of children and adult The normal human no fully active immune system at birth because of immaturity. It relies instead on passively transferred antibodies from the mother. This maternal antibody slowly decreases in concentration and for all practical purposes, has waned by 1 year. The infant own production of antibody begins to be meaningful at 7 or 8 months of age when the total of maternal and infant antibody is low. One has waned and the other is not up to full strength. This is age when many of the infectious disease processes of infancy begin /e.g. otitis media, pneumonia.
26. IMMUNOGLOBULIN PREPARETION Normal human Ig. Normal human Ig is an antibody-rich fraction, obtained from a pool of at least 1000 donors. The preparation should contain at least 90% intact IgG; it should be as free as possible from IgG aggregates; all IgG sub-classes should be present; there should be a low IgA concentration; the level of antibody against at least two bacterial species and two viruses should be ascertained Normal human Ig used to prevent measles in highly susceptible individuals and to provide temporary protection /up to 12 weeks/ against hepatitis A infection. Live vaccines should not normally be given for 12 weeks after an injection of normal human Ig.
27. Specific human Ig. These preparations are made from the plasma of patient who have recently recovered from an infection or are obtained from individuals who have been immunized against a specific infection. The advantages of Ig-s are: 1. freedom from hepatitis B 2. concentration of the antibodies into a small volume for intramuscular use. 3. stable antibody content, if properly stored.
30. Site of Administration Anterolateral aspect of the thigh in infants and deltoid muscle in older children or adult. Intramuscular Anterolateral aspect of the thigh or the upper arm Subcutaneous Over the insertion of left deltoid muscle Intradermal
