1.NounThe process by which a person is safely exposed in a controlled manner to a material that is designed to prime their immune system against that material.
"Immunization against influenza is important for all child-care workers."
2.NounOne such exposure.
"The first immunization a baby gets is against HBV."
3.NounThe process by which any organism's body develops immunity against a pathogen.
"Immunization via previous infection is not unusual among infectious diseases, but the degree and duration of such immunization varies by disease and depends on other factors as well (such as immunocapability and dietary sufficiency)."