Immunisation – protecting our children from disease
Glossary
antibody. A protein produced by the body’s immune system in response to a foreign substance (antigen). An antibody reacts specifically with the antigen that induced its formation and inactivates the antigen. Our bodies fight off an infection by producing antibodies.
antigen. Any foreign substance, usually a protein, that stimulates the body's immune system to produce antibodies. (The name antigen reflects its role in stimulating an immune response – antibody generating.)
attenuated vaccines. Vaccines are designed to stimulate antibody production without causing serious disease. To make an attenuated vaccine, a disease-causing microorganism is first isolated and then attenuated (made less virulent) by ageing it or altering its growth conditions (such as by depriving it of an essential nutrient). The vaccines for measles, mumps, and rubella are prepared in this way. Because this vaccine is actually a living microbe, it multiplies within your body and therefore causes a strong stimulation of the immune system.
bacterium (plural bacteria). A single-celled, microscopic organism without a distinct nucleus.
immune system. The cells, tissues and organs that assist the body to resist infection and disease by producing antibodies and/or altered cells that inhibit the multiplication of the infectious agent and provide resistance to disease.
immunisation. The process by which the body develops the capacity to combat a specific infection. Immunisation can be induced by introducing vaccines into the body. This is more correctly called vaccination or inoculation, but the word immunisation is used to mean the same thing.
toxins. Substances, produced by microorganisms, which affect the functioning of another organism.
vaccine. A preparation consisting of antigens of a disease-causing organism which, when introduced into the body, stimulates the production of specific antibodies or altered cells. This produces an immunity to the disease-causing organism. The antigen in the preparation can be whole disease-causing organisms (killed or weakened) or parts of these organisms.
virus. A submicroscopic infectious agent consisting of a nucleic acid (DNA or RNA) molecule surrounded by a protein coat. Viruses cannot replicate outside a living cell. More information can be found at How viruses work (How Stuff Works, USA).
Updated November 2011