FUNCTIONS OF THE IMMUNE SYSTEM

Under normal circumstances the immune system responds to foreign organism by production of antibodies and the stimulation of antigen-specific lymphocytes, leading to killing of the organism and neutralization of their toxic product (toxins). A major function of the immune system is surveillance of the cells of the body to ensure that they are not abnormal. Cell infected with viruses, malignant cell, or cells from another individual of the same species have protein markers on their outer membrane that act as a signal to the immune system to destroy them. The system to which these proteins belong is called the major histocompatibility complex (MHC) .

Immune responses are not always beneficial. They can contribute directly to pathological processes during infections and autoimmunity. The term hypersensitive or allergy are used when immune reaction produce tissue damage and harm the host; such reactions to an other wise harmless foreign substances may have severe effect and even lead to anaphylactic shock and death. In some cases for reasons that are not clear, normal cell may be wrongly identified as foreign or abnormal.

The immune system may develop antibodies and activate lymphocytes against them, producing autoimmune disease including systemic Lupus erythematosus, Myasthenia Gravis, diabetes and graves’ disease. Immune system also can develop by giving a vaccine to human or to animals.

Immunology

The term immunity indicates the condition of an individual who recovers form a disease and is no longer susceptible to that disease a broader definition of immunity all of the physiological mechanism that give an organism the ability to recognize foreign substances and neutralize or degrade them, with or without injury to the organism’s own tissue. Immunology is branch of medicined concerned with the body’s response to foreign substances.

History of Immunology

In attempt to prevent diseases, 15th- century Chinese practiced the custom inhaling dried powders of smallpox crusts to gain protection, but the inoculation of human smallpox materials was found to be hazardous. Edward Jenner observed that people who cought cowpox rarely contracted smallpox . In 1796 he induced cowpox in a young boy and later tried to infect the boy with smallpox, but the immunity provoked by the cowpox virus was effective against smallpox.

Louis Pasteur discovered in 1879 that neglected cultures of the bacteria that cause chickens chlorella lost much of their ability to cause the disease, whereas fresh cultures failed to infect chicken previously inoculated with old cultures. The introduction of dead or attenuated (weakened) microbes into the body to develop resistance to disease is called Vaccination (from the latin vacca; cow). Vaccination is used against such bacterial disease as cholera, dhphteria, and tetanus, and viral infection including hepatitis B, measles, polymielitis and rabies.

The work of Jenner and Pasteur marked the beginning of the field of immunology. Paul Ehrlich proposed the humoral theory of immunity, emphasizing the role of antibodies, protein produced by cells and released into the bloodstream, as the major agents of immunity. Russian biologist Elie Metchnikoff (1845-1946) developed the body’s scavenger cells, are the major detectors of foreign material and the primary defense system against infectious organisms. Both theory are correct.

Vaccination

Vaccination is the inoculation of a person (or animal) in order to bring about immunity to an infection (pathogenic) organism. The term (from the Latin Vacca, “cow”) originally meant immunization against smallpox, because the procedure originated in 1796 the milkmaids who had contracted the mild disease cowpox (vaccinia) were immune to smallpox. The development of cowpox has since led to the production of vaccines against a wide range of diseases.

Vaccination is bases on the ability of a person’s immune system to respond much more effectively and rapidly to a microorganism the second or third time that the elements of the immune system encounter the invading organism. It was in this way, for example, that the milk maids immune system were “primed” by the cowpox virus to respond effectively to the closely related smallpox virus.

A vaccine may consist of living organisms that are weakened or attenuated, in a laboratory so that they create immunity but do not cause disease. It may also consist of related organisms that cause a similar but milder disease, of killed organisms, or of extracts of the organisms that can induce the desired immune response and subsequent immunity but do not cause the disease. Periodic booster immunization is recommended with most vaccines, because the immunity caused by the initial inoculation may decrease with time. The time interval before booster shots are required varies greatly with the type of vaccine.

Vaccination has occasional complications. Thus patients with a poorly functioning immune system have particular problems with certain vaccines. Immunodeficient patients may develop acute poliomyelitis from the attenuated virus vaccine, for example, although they do not develop the disease from killed polio virus. Transient problems with mild fevers, muscle aches, and tenderness at the inoculation site are also common to many vaccines. Control of serious disease by vaccination, however, is usually worth such risks.

Most of the exceptionally effective vaccines are viral vaccine, such as those for measles, mumps, and rubella. Influenza vaccines are recommended for individuals at high risk for serious infections of the lungs. Because influenza strains are different almost every year, vaccination should be carried out yearly in the susceptible population. Vaccination for yellow fever and certain types of hepatitis are also of proven efficacy. Also available are vaccines for certain bacterial infections, such as typhoid fever, cholera, diphtheria, whooping cough, and tetanus. Among new vaccines being developed are vaccines against malaria, leprosy, and dengue fever. Researchers are also exploring the production of multipurpose vaccines though genetic engineering using entitles such as the vaccinia virus or the bacterium known as BCG to carry genes from several disease organisms.

Vaccine Administration

Vaccine administration includes all of this activity:

• Preparation
• Infection Control
• Vaccine preparation
• Administration

Each of that activity will describe more detail on the next articles, and must attention carefully on doing vaccine applications. Appropriate vaccine administration is critical to vaccine effectiveness. The recommended site, route and dosage for each vaccine are based on clinical trials, practical experience and theoretical considerations. The following information provides general guidelines for administration of vaccines for those who administer vaccines, as well as those in training, education and supervisory positions.

This information should be used in conjunction with professional standards for medication administration, vaccine manufacturers' product guidelines, CDC's Advisory Committee on Immunization Practices (ACIP) General Recommendations on Immunization, the American Academy of Pediatrics' (AAP) Report of the Committee on Infectious Diseases Red Book, and state/agency-related policies and procedures. An education plan that includes competency-based training on vaccine administration should be considered for all persons who administer vaccines to children or adults. All the vaccine activity for every diseases vaccine must follow the vaccine schedule that determine by the area conditions and current situation that sometime changes every time.