vac·​cine | \ vak-ˈsēn How to pronounce vaccine (audio) , ˈvak-ˌsēn\

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

Keep scrolling for more

Other Words from vaccine

vaccine adjective

Examples of vaccine in a Sentence

Recent Examples on the Web

Ironically, Steel had been due to get the MMR vaccine within days. Nina Shapiro, The Seattle Times, "Fear, resentment — and more demand for vaccines as one Washington county grapples with measles outbreak," 1 Apr. 2019 All the hand-washing and disinfectant in the world can’t compare to getting a vaccine meant to protect you from the inside out. Colleen Stinchcombe, SELF, "These 7 Things at Your Office Are Especially Germy," 22 Feb. 2019 Clark County says only 78% of its children age 6 to 18 have received the recommended two doses of the MMR vaccine, for measles, mumps and rubella. The Editorial Board, WSJ, "Didn’t We Already Beat Measles?," 12 Feb. 2019 For the BCG vaccine to work, researchers say patients must be given two doses, an initial injection followed by a second shot of the vaccine a month later. Daniel Wilson, sacbee, "Study shows tuberculosis vaccine may reverse Type 1 diabetes," 21 June 2018 Currently, the process of designing, testing, and manufacturing a vaccine to prevent the spread of a new pathogen takes years. R. Daniel Bressler, Vox, "“Designer bugs”: how the next pandemic might come from a lab," 6 Dec. 2018 Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases, is spearheading the federal effort for a universal vaccine. WSJ, "New Ideas to Fight the Flu," 20 Nov. 2018 Treatment typically involves checking for tetanus immunization and shots of immune globulin as well as a rabies vaccine. Alexandria Hein, Fox News, "Georgia boy, 4, treated for rabies after mom shoots raccoon dead in porch attack," 19 Sep. 2018 For a fast-food worker making $7.25 an hour, a vaccine would wipe out an entire day's pay. Steve Harrison, charlotteobserver, "After a Hardee's hepatitis A scare, here's what the county could do to reduce risk," 28 June 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.

See More

First Known Use of vaccine

1882, in the meaning defined above

History and Etymology for 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 -ine entry 1; in extended sense, "preparation of organisms administered to produce immunity," in part borrowed from French vaccin, masculine derivative of vaccine "cowpox, matter from cowpox pustules," borrowed from New Latin or English

Keep scrolling for more

Learn More about vaccine

Statistics for vaccine

Last Updated

17 Apr 2019

Look-up Popularity

Time Traveler for vaccine

The first known use of vaccine was in 1882

See more words from the same year

Keep scrolling for more

More Definitions for vaccine



English Language Learners Definition of vaccine

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


vac·​cine | \ vak-ˈsēn How to pronounce vaccine (audio) , ˈvak-ˌsēn\

Kids Definition of vaccine

: 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


vac·​cine | \ vak-ˈsēn, ˈvak-ˌ How to pronounce vaccine (audio) \

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 chicken pox vaccine also : a mixture of several such vaccines measles-mumps-rubella vaccine

Keep scrolling for more

More from Merriam-Webster on vaccine

Rhyming Dictionary: Words that rhyme with vaccine

Spanish Central: Translation of vaccine

Nglish: Translation of vaccine for Spanish Speakers

Britannica English: Translation of vaccine for Arabic Speakers Encyclopedia article about vaccine

Comments on vaccine

What made you want to look up vaccine? Please tell us where you read or heard it (including the quote, if possible).


a secret plot to overthrow a government

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Latin Quiz

  • roman forum
  • Which of the following months comes from a Latin word for “ten”?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!