vaccinate

American  

[vak-suh-nayt] / 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

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Etymology

Origin of vaccinate

First recorded in 1800–10; back formation from vaccination

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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

Although official records suggested 90-95% coverage in some areas, health workers found children without records and families reluctant to vaccinate.

From BBC ● Sep. 30, 2026

“Every day there are opportunities to vaccinate children and protect them that we’re missing because those vaccines aren’t yet in the field,” Fiscus said.

From The Wall Street Journal ● Sep. 16, 2026

Nelson, who is also a nurse administrator in Washington state, said most parents vaccinate their children in the end, once they get solid information from their healthcare provider or school nurse.

From Salon ● Sep. 12, 2026

Australian wildlife workers have launched an unprecedented effort to vaccinate wild populations of little penguins against the highly contagious H5N1 avian influenza.

From Barron's ● Aug. 20, 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

Castro and Raimondo said they are suffering only mild symptoms while Schiff said he is “feeling fine” — and touted the value of vaccinates and boosters.

From Washington Post ● Apr. 6, 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.

In Pennsylvania’s Lancaster County, where around 400 people have been infected and three have died, 87.6% of kindergartners in the 2025-26 school year were fully vaccinated against measles.

From The Wall Street Journal ● Oct. 7, 2026

The agency also said the woman had been "vaccinated and had immunity to dangerous infections with which she worked".

From Barron's ● Oct. 7, 2026

Of about 40,000 children identified in Birsa, roughly 27,000 had been vaccinated, Gautam said.

From BBC ● Sep. 30, 2026

Nearly 20,000 young people have been vaccinated in Wales through catch-up clinics, following a deadly outbreak of meningitis B in Kent earlier this year.

From BBC ● Sep. 29, 2026

While forty thousand people have been vaccinated since the epidemic began, the ultimate goal is to inoculate a hundred thousand Haitians.

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

One mother, who asked to speak anonymously to protect her children, told AFP she decided to hold off on vaccinating them after watching the videos.

From Barron's ● Oct. 2, 2026

But the CDC does recommend vaccinating infants when they are between 6 and 11 months old if they’re either traveling internationally or at risk of measles exposure during an outbreak.

From Los Angeles Times ● May 6, 2026

"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

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

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Related Words

• immunize
• inject
• inoculate
• protect
• treat

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