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.
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
Wayne Biddle Those benefits can include preventive care, such as annual physicals, immunizations, and well-baby visits. —Consumer Reports
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
Ken MillerExamples of immunization in a Sentence
Recent Examples on the Web
By then, 42 people, three-quarters of whom were not up to date on their whooping cough immunizations, had been hospitalized for whooping cough since the outbreak began, according to the Louisiana Department of Health.
—Rosemary Westwood, NPR, 28 Oct. 2025
Merle is a healthy 7-year-old great Pyrenees who has received veterinarian care with the proper immunizations and tick prevention throughout his life.
—Maria Azzurra Volpe, MSNBC Newsweek, 25 Oct. 2025
In Sokoto, one of the most challenging states for vaccine uptake, the Emergency Operations Center brought these women together to support immunization efforts last month.
—Dr. Tunji Funsho, Time, 24 Oct. 2025
Now, parents of infants too young for a measles vaccine can’t choose a daycare that requires immunization.
—Audrey Dutton, CNN Money, 23 Oct. 2025
See All Example Sentences for immunization
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Rosemary Westwood, NPR, 28 Oct. 2025
Merle is a healthy 7-year-old great Pyrenees who has received veterinarian care with the proper immunizations and tick prevention throughout his life.
—Maria Azzurra Volpe, MSNBC Newsweek, 25 Oct. 2025
In Sokoto, one of the most challenging states for vaccine uptake, the Emergency Operations Center brought these women together to support immunization efforts last month.
—Dr. Tunji Funsho, Time, 24 Oct. 2025
Now, parents of infants too young for a measles vaccine can’t choose a daycare that requires immunization.
—Audrey Dutton, CNN Money, 23 Oct. 2025
See All Example Sentences for immunization
Cite this Entry
“Immunization.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/immunization. Accessed 29 Oct. 2025.
Copy CitationMedical Definition
immunization
noun
im·mu·ni·za·tion
variants
also British immunisation
Love words? Need even more definitions?
Merriam-Webster unabridged
Share