immunization

noun

im·​mu·​ni·​za·​tion ˌi-myə-nə-ˈzā-shən 

also i-ˌmyü-nə-

plural immunizations

: the act of making someone or something immune or the state of being immune : the act or result of immunizing someone or something: such as

a

: the production of immunity in a living organism against a disease or pathogenic agent

Full immunization occurs two weeks after inoculation.

The plasmids used for immunization have been altered to carry genes specifying one or more antigenic proteins normally made by a selected pathogen …

—David B. Weiner et al.

also : treatment (as by vaccination) for the purpose of making an organism immune to a disease or pathogenic agent : the administration of an immune-producing substance

Measles is the single most infectious common disease—one person with measles who blunders into a crowded room will give it to almost everyone. If there were no immunization, measles would be universal.

—Wayne Biddle

Those benefits can include preventive care, such as annual physicals, immunizations, and well-baby visits.

—Consumer Reports

b

: the providing of protection or exemption from something harmful or unwanted (such as legal action)

immunization from liability

The Interior Department is negotiating with other private landowners to extend similar immunization from prosecution to those who agree to avoid activities that might hurt the bird's chances of survival.

—Ken Miller

Examples of immunization in a Sentence

Recent Examples on the Web

The Idaho Statesman began running investigative stories on auto airbag safety, early childhood education, immunization and workers’ compensation for farm workers. —Idaho Statesman, 16 Dec. 2025

Both offer the option to receive multiple vaccines at once, and the cost of immunization at these pharmacies is covered entirely by most insurance companies. —Mary Walrath-Holdridge, USA Today, 16 Dec. 2025

State governments have the final authority over vaccine policy, however, and can set mandates, such as immunization requirements for children to enroll in public schools. —Kristen Jordan Shamus, Freep.com, 14 Dec. 2025

Florida‘s childhood immunization rates are already on the decline. —Romy Ellenbogen, Miami Herald, 12 Dec. 2025

Word History

First Known Use

1889, in the meaning defined above

Rhymes for immunization

• abbreviation
• abomination
• acceleration
• accentuation
• accommodation
• accreditation
• acculturation
• accumulation
• acetylation
• adjudication
• administration
• adulteration

Kids Definition

immunization

noun

im·​mu·​ni·​za·​tion

ˌim-yə-nə-ˈzā-shən

: treatment (as with a vaccine) to produce immunity to a disease

Medical Definition

immunization

noun

im·​mu·​ni·​za·​tion

variants also British immunisation

ˌim-yə-nə-ˈzā-shən 

: the production of immunity in a living organism against a disease or pathogenic agent

also : treatment (as by vaccination) for the purpose of making an organism immune to a disease or pathogenic agent : the administration of an immune-producing substance

immunization against polio