vaccine

noun vac·cine \ vak-ˈsēn , ˈvak-ˌsēn \

|Updated on: 7 Aug 2018

Definition of vaccine

: a preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease

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vaccine

adjective

See vaccine defined for English-language learners

See vaccine defined for kids

Recent Examples of vaccine from the Web

Current vaccines are made from another related virus called vaccinia.

— NBC News, "Now there's a drug to treat smallpox, just in case," 13 July 2018
Only four cases were found in Mbandaka, and the vaccine was rolled out there almost immediately.

— New York Times, "Ebola Outbreak in Central Africa Is ‘Largely Contained’," 28 June 2018
The vaccine is also recommended for men up to age 21 and women up to age 26.

— molly sullivan, sacbee, "HPV vaccines save lives but could save more, UCD Cancer Center says. It's spreading the word," 8 June 2018
While just about everyone should get a flu shot ever year, the dog flu vaccine isn’t recommended for every pup, according to the American Veterinary Medical Foundation.

— sarah klein, Health.com, "A New Study Says 'Dog Flu' Could Be the Next Swine Flu. How Worried Should You Really Be?," 7 June 2018
The vaccine was tested in nearly 12,000 people in Guinea and Sierra Leone.

— julia belluz, Vox, "In a first, the Ebola vaccine is being deployed to try to stop an outbreak from spreading.," 16 May 2018
But with two doses, the MMR vaccine is estimated to be at least 97 percent effective at preventing it.

— andy marso, kansascity, "Kansas City reaches important milestone in its two measles outbreaks | The Kansas City Star," 11 May 2018
Given the fraught history of the (consistently debunked) allegations that vaccines are tied to autism spectrum disorders, there may be an impulse in certain corners to bring up vaccinations as a potential root for this rise in diagnoses.

— sy mukherjee, Fortune, "Brainstorm Health: Autism Rates Rise, Genetic Depression Risk, Bill Gates Flu Vaccine," 27 Apr. 2018
Hepatitis A vaccines can be given at any medical facility and are often out of pocket if compliant with the federal Affordable Care Act.

— thomas novelly, The Courier-Journal, "With 214 confirmed cases of hepatitis A in Louisville, officials recommend vaccines," 16 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vaccine.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of vaccine

earlier, "fluid from cowpox pustules used in inoculation," noun use of vaccine "of cowpox" (in the phrases vaccine disease, vaccine matter), borrowed from New Latin vaccina (in variolae vaccinae "cowpox"), going back to Latin, feminine of vaccīnus "of or from a cow," from vacca "cow" (perhaps akin to Sanskrit vaśā "cow") + -īnus ¹-ine; in extended sense, "preparation of organisms administered to produced immunity," in part borrowed from French vaccin, masculine derivative of vaccine "cowpox, matter from cowpox pustules," borrowed from New Latin or English

NEW! Time Traveler

First Known Use: 1882

in the meaning defined above

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VACCINE Defined for English Language Learners

vaccine

noun

Definition of vaccine for English Language Learners

medical : a substance that is usually injected into a person or animal to protect against a particular disease

VACCINE Defined for Kids

vaccine

noun vac·cine \ vak-ˈsēn , ˈvak-ˌsēn \

Definition of vaccine for Students

: a preparation containing usually killed or weakened microorganisms (as bacteria or viruses) that is given usually by injection to increase protection against a particular disease

History for vaccine

In the late 1700s the English doctor Edward Jenner investigated the old belief that people who contracted a mild disease called cowpox from cows thereby became immune to smallpox, a much more dangerous disease. Jenner documented 23 such cases, where people inoculated with matter from cowpox sores came down with cowpox but then did not contract smallpox. Because variolae vaccinae, literally, “cow pustules,” was the medical Latin name for cowpox, the virus-containing material used for inoculations eventually came to be called vaccine.

Medical Dictionary

vaccine

noun vac·cine \ vak-ˈsēn, ˈvak-ˌ \

medical Definition of vaccine

1 : matter or a preparation containing the virus of cowpox used to vaccinate a person against smallpox

2 : a preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease