im·​mu·​ni·​za·​tion | \ ˌi-myə-nə-ˈzā-shən How to pronounce immunization (audio) also i-ˌmyü-nə- \
plural immunizations

Definition of immunization

: 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

First Known Use of immunization

1889, in the meaning defined above

Learn More About immunization

Time Traveler for immunization

Time Traveler

The first known use of immunization was in 1889

See more words from the same year

Dictionary Entries Near immunization




See More Nearby Entries 

Statistics for immunization

Cite this Entry

“Immunization.” Dictionary, Merriam-Webster, Accessed 28 May. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for immunization


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

Kids Definition of immunization

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


variants: also British immunisation \ ˌim-​yə-​nə-​ˈzā-​shən How to pronounce immunization (audio) \

Medical Definition of immunization

: 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

More from Merriam-Webster on immunization

Nglish: Translation of immunization for Spanish Speakers

Britannica English: Translation of immunization for Arabic Speakers


Test Your Vocabulary

Eponyms: Words Named After People

True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!