immunization
Americannoun
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immunizations
plural
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the fact or process of becoming immune, as against a disease.
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Finance. a method of protection against fluctuating bond interest rates by investing in securities having different yields and terms.
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The process of inducing immunity to an infectious organism or agent in an individual or animal through vaccination.
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A vaccination that induces immunity. A recommended schedule of immunizations for infants and young children includes vaccines against diphtheria, polio, tetanus, measles, mumps, and rubella.
Usage
What’s the difference between immunization, vaccination, and inoculation? In the context of medicine, the words immunization, vaccination, and inoculation are often used in overlapping ways, and for good reason—they all involve the process of introducing a substance (especially a vaccine) into a person’s body with the goal of preventing them from getting a particular disease. Vaccination is the most specific of the three terms, because it always involves introducing a vaccine, which usually consists of a small amount of a killed, weakened, or otherwise modified version of a disease (such as a virus or bacterium). While inoculation has other meanings outside the context of medicine, in modern healthcare it’s typically used interchangeably with vaccination (though it’s used less commonly). Immunization is slightly different—it refers to the process of providing immunity from a specific disease. While the goal of vaccinating someone is often to immunize them, not all vaccines provide permanent immunity. Some vaccines provide what amounts to long-term immunity, while others only lead to a temporary protection, after which the body “forgets” how to make certain antibodies. In these cases, a booster shot or dose is often required, consisting of a follow-up vaccination to boost or renew the protection gained from the earlier vaccination. Both vaccination and inoculation can refer to a shot or dose, as opposed to the process of providing or receiving such doses, as in I’m scheduled to get a vaccination on Friday. The word immunization can be used in the same way to refer to such a vaccination when it’s one that provides immunity, as in Have you received all of your immunizations?Want to learn more? Read the full breakdown of the difference between immunize, vaccinate, and inoculate.
Discover More
Frequently, schoolchildren are required by state law to be immunized against certain diseases. Because of such widespread immunization, many diseases that used to be fairly common, including smallpox, tetanus, and whooping cough, have become rare.
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Etymology
Origin of immunization
Compare meaning
How does immunization compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
Immunization is the process of getting a shot that boosts your body's defenses against a certain disease. Before international travel, you may need to get additional immunizations. Strictly speaking, immunization is action of stimulating your immune system to fight off infection, with the help of a vaccine. You can also use immunization interchangeably with vaccination or inoculation, so you might say, "While I was at the doctor, I went ahead and got my flu immunization." The word comes from immune, "exempt from disease," and its Latin root, which means "exempt."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
By obstructing vaccine deliveries and restricting immunization teams in the areas they control, they have left nearly five million Yemeni children without routine vaccinations.
From The Wall Street Journal ● Aug. 24, 2026
"States and territories are advised to review" the Trump administration's recommendations on "immunization requirements for contexts such as school enrollment and attendance," the order states.
From Barron's ● Aug. 10, 2026
Anyone who may have been exposed to measles should first determine whether they have been vaccinated against measles by checking their immunization records, the public health department advised.
From Los Angeles Times ● Jun. 14, 2026
His decision likely cost him billions of dollars but accelerated the immunization effort.
From The Wall Street Journal ● Apr. 24, 2026
Valerie Jarrett helped me arrange placements in the mayor’s office and the city health department, where Allies would work on a neighborhood-based childhood immunization project.
From "Becoming" by Michelle Obama
There are five immunizations required as a condition of entry into kindergarten in California: polio; DTaP, which protects against diphtheria, tetanus and pertussis; hepatitis B; MMR; and varicella, or chickenpox.
From Los Angeles Times ● Aug. 15, 2026
The bottom line is that childhood immunizations save lives.
From Los Angeles Times ● Aug. 12, 2026
It would also likely reduce immunizations by requiring more trips to the doctor’s office.
From The Wall Street Journal ● Aug. 11, 2026
Other diseases on the AAP’s recommended schedule for immunizations include chickenpox, measles and polio.
From The Wall Street Journal ● Jan. 26, 2026
When she takes him in his pram for his immunizations at the pediatrician’s, she stands outside the room and plugs up her ears.
From "The Namesake" by Jhumpa Lahiri
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
