im·​mu·​ni·​za·​tion ˌi-myə-nə-ˈzā-shən How to pronounce immunization (audio)
 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
: 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
: 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 Despite a sharp decline in routine childhood immunizations during the pandemic that’s been slow to rebound, Aho said the latest immunization data from the state shows recent improvements to that rate. Annie Berman, Anchorage Daily News, 17 Sep. 2023 Even though rubella has been totally eliminated from the U.S., immunization continues because of rubella in other countries. Parents Editors, Parents, 3 Sep. 2023 Walmart offering free screenings, low-cost shots Saturday Walmart is holding a Wellness Day at which people can obtain free screenings and affordable immunizations from 10 a.m. to 2 p.m., Saturday, Aug. 19, at all Walmart stores, including the one in Naperville. Michelle Mullins, Chicago Tribune, 17 Aug. 2023 The immunization is called nirsevimab, and has the brand name Beyfortus, and is being distributed by AstraZeneca and Sanofi. Rong-Gong Lin Ii, Los Angeles Times, 11 Aug. 2023 At-risk people attending large gatherings should consider a repeat immunization with vaccines on the market, rather than wait for the next crop of boosters, said Thomas Russo, chief of the division of infectious diseases at the University of Buffalo’s medical school. Matthew Griffin, Anchorage Daily News, 10 Aug. 2023 The immunization, called Beyfortus, is manufactured by Sanofi and AstraZeneca. Nick Blackmer, Verywell Health, 25 July 2023 In addition, a third type of RSV immunization might also be available this year, pending CDC sign-off. Dr. Evgeniya Jenny Rakitina, ABC News, 25 Aug. 2023 Make sure physicals and immunizations are up to date. Dr. Shanessa Fenner, Essence, 18 Aug. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'immunization.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1889, in the meaning defined above

Time Traveler
The first known use of immunization was in 1889

Dictionary Entries Near immunization

Cite this Entry

“Immunization.” Dictionary, Merriam-Webster, Accessed 4 Oct. 2023.

Kids Definition


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

Medical Definition


variants also British immunisation
: 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

Last Updated: - Updated example sentences
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