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

The monoclonal antibodies and maternal vaccination both protect babies through passive immunization, which means the infants are given antibodies. —Tara Haelle, Scientific American, 23 Sep. 2025

Flu vaccine can also be given at the same visit as the respiratory syncytial virus (RSV) immunization. —Dr. Kristina Bryant, Boston Herald, 21 Sep. 2025

Many of the new panelists have expressed skepticism of vaccines or lack experience in the subject, sparking backlash from the medical and science communities, which have released their own immunization recommendations that conflict in important ways with the ACIP advice. —Chantelle Lee, Time, 19 Sep. 2025

The questions the panel will vote on have not been disclosed, but speculation has run high that the panel will endorse drastic changes to the current immunization recommendations, including the guidance to immunize newborns against hepatitis B. —The Hill, 18 Sep. 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