IMMUNIZATION

n. process of rendering insusceptible to a disease (also immunisation)

For financial immunization, see Immunization (finance). Immunization, or immunisation, is the process by which an individual is exposed to an agent that is designed to fortify his or her immune system against that agent. The material is known as an immunogen. Immunization is the same as inoculation and vaccination in that inoculation and vaccination use a viable infecting agent like immunization does. When the human immune system is exposed to a disease once, it can develop the ability to quickly respond to a subsequent infection. Therefore, by exposing an individual to an immunogen in a controlled way, their body will then be able to protect itself from infection later on in life.
See more at Wikipedia.org...

Immunization /im·mu·ni·za·tion/ the process of rendering a subject immune, or of becoming immune. active immunization stimulation with a specific [more]Immunization - Community and Resources

Noun
1. the act of making immune (especially by inoculation)
(synonym) immunisation
(hypernym) protection
(hyponym) inoculation, vaccination
(derivation) immunize, immunise, inoculate, vaccinate

Immunizations, or vaccinations, work by stimulating the immune system, the natural disease-fighting system of the body. The healthy immune system is able to recognize invading bacteria and viruses and produce substances (antibodies) to destroy or disable them. Immunizations prepare the immune system to ward off a disease. To immunize against viral diseases, the virus used in the vaccine has been weakened or killed. To immunize against bacterial diseases, it is generally possible to use only a small portion of the dead bacteria to stimulate the formation of antibodies against the whole bacteria. In addition to the initial immunization process, it has been found that the effectiveness of immunizations can be improved by periodic repeat injections or "boosters." Also see Immunizations (in the plural) and Immunization of a specific type (such Immunization, Polio).