In medicine immunization is the process by which an individual is exposed to a material that is designed to prime his or her immune system against that material. The material is known as an immunogen. Immunization is different from inoculation or vaccination in that inoculation and vaccination use a viable infecting agent (i.e., it can make the individual sick) while immunization does not use a viable agent. Medicine on the Web NLM (National Library of Medicine, contains resources for patients and healthcare professionals) Virtual Hospital (digital health sciences library by the University of Iowa) Online Medical Dictionary Collection of links to free medical resources Categories: Medicine | Health ... An antigen is a molecule that stimulates the production of antibodies. ... Inoculation was a method of minimising the harm done by infection with smallpox. ... Vaccination is a term coined by Edward Jenner for the process of administering live, albeit weakened, microbes to patients, with the intent of conferring immunity against a targeted form of a related disease agent. ...

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.