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

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

Shares of Moderna were down more than 30% for the year entering Monday, fueled in large part by a string of moves by the Trump administration to change vaccine policy and undermine immunizations. —Annika Kim Constantino, CNBC, 30 June 2025

Though my mother had diligently filled in information about my weight, height, immunizations, and first words, the page for baby’s first haircut was left blank. —Jhumpa Lahiri, New Yorker, 30 June 2025

Gavi, at its most basic level, is Costco for immunizations, wielding its massive purchasing power to buy vaccines in bulk for cheap. —Hana Kiros, The Atlantic, 28 June 2025

The court's decision on preventive care likely will protect other existing preventive services under ACA, including treatment for blood pressure screenings, as well as birth control, breast and lung cancer screenings, immunizations, and more. —Nina Totenberg, NPR, 27 June 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 creation of immunity usually against a particular disease

especially : treatment (as by vaccination) of an organism for the purpose of making it immune to a particular pathogen

immunization against polio