immunization

American  

[im-yuh-nuh-zey-shuhn, ih-myoo-] / ˌɪm yə nəˈzeɪ ʃən, ɪˌmyu- /

noun

1. the fact or process of becoming immune, as against a disease.

2. Finance. a method of protection against fluctuating bond interest rates by investing in securities having different yields and terms.

---

immunization Scientific  

/ ĭm′yə-nĭ-zā′shən /

1. The process of inducing immunity to an infectious organism or agent in an individual or animal through vaccination.

2. 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.

---

immunization Cultural  

1. The process of inducing immunity, usually through inoculation or vaccination.

---

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.

Other Word Forms

• hyperimmunization
  noun
• nonimmunization
  noun

Etymology

Origin of immunization

First recorded in 1890–95; immunize + -ation

Compare meaning

How does immunization compare to similar and commonly confused words? Explore the most common comparisons:

• vaccination vs. immunization

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

The Advisory Committee on Immunization Practices, or ACIP, recommended that if an infant’s mother tests negative for hepatitis B, parents should consult a doctor about whether the baby needs an early vaccine dose.

From The Wall Street Journal • Dec. 5, 2025

The CDC’s Advisory Committee on Immunization Practices no longer recommends that all newborns get the first dose of the vaccine within 24 hours of birth.

From MarketWatch • Dec. 5, 2025

The Thursday meeting of the CDC committee, called the Advisory Committee on Immunization Practices, gives Kennedy the best shot yet at making a material change to how vaccines are used in the U.S.

From Barron's • Dec. 3, 2025

The changes were expected and were already previewed by recommendations made two weeks ago by the CDC’s powerful Advisory Committee on Immunization Practices.

From Los Angeles Times • Oct. 6, 2025

We call them by different names: Immunization or Radiology or what not; but the dreams which lure us into the adventures from which we learn are always at bottom the same.

From The Doctor's Dilemma: Preface on Doctors by Shaw, Bernard