vaccinate

American  

[vak-suh-neyt] / ˈvæk səˌneɪt /

verb (used with object)

• vaccinates,
  present (3rd person singular)
• vaccinated,
  past participle,  past
• vaccinating
  present participle

1. to inoculate with the vaccine of cowpox so as to render the subject immune to smallpox.

2. to inoculate with the modified virus of any of various other diseases, as a preventive measure.

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verb (used without object)

• vaccinates,
  present (3rd person singular)
• vaccinated,
  past participle,  past
• vaccinating
  present participle

1. to perform or practice vaccination.

vaccinate British  

/ ˈvæksɪˌneɪt /

verb

1. to inoculate (a person) with a vaccine so as to produce immunity against a specific disease

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Usage

What’s the difference between vaccinate, inoculate, and immunize? In the context of medicine, vaccinate, inoculate, and immunize are often used in overlapping ways, and for good reason—they all involve introducing a substance (especially a vaccine) into a person’s body with the goal of preventing them from getting a particular disease. Vaccinate 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 inoculate has other meanings outside the context of medicine, in modern healthcare it’s typically used interchangeably with vaccinate (though it’s used less commonly). Immunize is slightly different—it means to provide 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. Want to learn more? Read the full breakdown of the difference between vaccinate, inoculate, and immunize.

Other Word Forms

Derived Forms

• vaccinator
  noun
• prevaccinate
  verb (used with object)
• revaccinate
  verb (used with object)
• unvaccinated
  adjective

Inflected Forms

Participles

• vaccinating
  present
• vaccinated
  past

Conjugated Forms

Present

• vaccinate
  simple
• vaccinates
  simple
• have vaccinated
  perfect
• has vaccinated
  perfect
• am vaccinating
  progressive
• are vaccinating
  progressive
• is vaccinating
  progressive
• have been vaccinating
  perfect progressive
• has been vaccinating
  perfect progressive

Past

• vaccinated
  simple
• had vaccinated
  perfect
• was vaccinating
  progressive
• were vaccinating
  progressive
• had been vaccinating
  perfect progressive

Future

• will vaccinate
  simple
• will have vaccinated
  perfect
• will be vaccinating
  progressive
• will have been vaccinating
  perfect progressive

Etymology

Origin of vaccinate

First recorded in 1800–10; back formation from vaccination

Explanation

To vaccinate is to immunize someone against a disease. Babies are usually vaccinated against many diseases soon after birth. A vaccine is a type of medicine that makes you resistant (immune) to a disease like polio. To give someone such a medicine is to vaccinate them. You can use this word in a few ways. A doctor is usually the person who vaccinates a child (or older person) by administering a vaccine. You can also say the parents have vaccinated their children by making the decision to do so. Animals can be vaccinated too, like dogs are vaccinated against rabies.

Example Sentences

See Examples For:

vaccinate vaccinates vaccinated vaccinating

"Trying to vaccinate wild populations is almost impossible, partly because you need two doses of the vaccine," Todd told AFP.

From Barron's ● Aug. 20, 2026

The Southwest Utah Public Health Department struggled to persuade parents to vaccinate their children despite the disease’s spread, said David Heaton, the department’s spokesman.

From The Wall Street Journal ● Jun. 13, 2026

UK advisers have said a widespread NHS catch-up campaign to vaccinate all teenagers against MenB is not cost-effective but will keep that decision under review.

From BBC ● Jun. 12, 2026

“I figured the hospital was already pissy with me because we didn’t vaccinate at all,” he told ProPublica.

From Salon ● May 7, 2026

We imagined them liberating Angola and marching right on up the Congo River to vaccinate us all!

From "The Poisonwood Bible" by Barbara Kingsolver

The new U.S. vaccination guidelines are much closer to those of Denmark, which routinely vaccinates its children against only 10 diseases.

From Los Angeles Times ● Jan. 5, 2026

Brazil vaccinates its population against hepatitis A, but given the magnitude of this advises people to still avoid consuming water or food that might be contaminated with water from the floods.

From BBC ● May 25, 2024

Refusing to import chicken meat from the United States if it vaccinates is a tempting retaliatory measure.

From Science Magazine ● Apr. 6, 2023

After all, she notes, with the exception of rabies, no one vaccinates against an infectious disease in people who are already infected.

From New York Times ● Oct. 10, 2022

If poor judgment is used in caring for the vaccinated hogs, and the person who vaccinates them uses careless methods, heavy losses from acute indigestion, blood poisoning, or hog-cholera may occur.

From Common Diseases of Farm Animals by R. A. Craig, D.V.M.

Two people who were not vaccinated against measles have died of the virus in Pennsylvania, health officials said.

From BBC ● Aug. 25, 2026

Researchers found that vaccinated adults had a 24% lower risk of dementia compared with those who did not receive the vaccine.

From Science Daily ● Aug. 25, 2026

“Anyone who hasn’t received a 2025-26 dose, or is due for the second dose, is encouraged to get vaccinated now, before the next COVID-19 surge,” according to a slide in Pan’s presentation to health professionals.

From Los Angeles Times ● Aug. 14, 2026

The experts looked at several studies, including one which showed that three out of four non-human primates vaccinated with Ervebo survived Bundibugyo, compared with one out of four control animals.

From Barron's ● Aug. 7, 2026

Virgin-soil death rates for smallpox are hard to establish because for the last century most potential research subjects have been vaccinated.

From "1491" by Charles C. Mann

"We are hoping that government will get this right in vaccinating the entire herd with speed," says Ntuthuko Shezi, head of investment company Livestock Wealth.

From BBC ● Feb. 19, 2026

It doesn’t want to spend money vaccinating children against bugs they are unlikely to encounter, even if they could be hospitalized if they do.

From The Wall Street Journal ● Jan. 6, 2026

Another study, based on data from Wales, found that vaccinating people against shingles may lower their risk of getting dementia by 20%.

From MarketWatch ● Nov. 1, 2025

Ms Crawford, chief executive of Age Scotland, said the criteria for vaccinating people, particularly between the age of 65 to 74, felt confusing.

From BBC ● Sep. 17, 2025

All of the other Zanmi Lasante projects in the villages around Cange had been interrupted—its programs for women’s literacy, for vaccinating children, for sanitation and clean water, for distributing condoms and other AIDS-prevention measures.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

Related Words

• immunize
• inject
• inoculate
• protect
• treat