booster shot


: a supplementary dose of an immunizing agent administered as an injection

called also booster, booster dose

Example Sentences

He had to get two booster shots at his latest checkup.
Recent Examples on the Web The main worry is that millions of Chinese people — almost 1 in 3 over the age of 60, according to official figures — haven’t had a third booster shot, leaving them more exposed to serious illness. Marie Brockling, NBC News, 17 Dec. 2022 Fewer than 60% of Chinese have had a booster shot, government data shows, including 40% of those age 80 and older. Liyan Qi And Raffaele Huang, WSJ, 1 Dec. 2022 To date, only two-thirds of Americans are fully vaccinated, and only one-third have had a booster shot. Roni Caryn Rabin, New York Times, 31 Aug. 2022 There are 285,970 people who are partially immunized; about 690,000 have had a booster shot. Lara Farrar, Arkansas Online, 5 July 2022 Those eligible include people who are unvaccinated or haven’t had a booster shot, as well as pregnant women, people at least 65 years old, and anyone with a medical condition that puts them at high risk for serious illness. Nanette Asimov, San Francisco Chronicle, 6 Apr. 2022 Vaccines continue to protect against the worst outcomes, but only about 60% of Americans older than 65 have had a first booster shot, according to federal data. Eduardo Medina,, 3 Apr. 2022 More than 95% of people aged 12 and over are fully vaccinated and more than 70% of adults have had a booster shot. Matthew Brockett,, 15 Mar. 2022 In Britain, 85% of people age 12 and up have had two vaccine doses and almost two-thirds have had a third booster shot. Jill Lawless, Anchorage Daily News, 21 Feb. 2022 See More

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

Word History

First Known Use

1944, in the meaning defined above

Time Traveler
The first known use of booster shot was in 1944

Dictionary Entries Near booster shot

Cite this Entry

“Booster shot.” Dictionary, Merriam-Webster, Accessed 4 Feb. 2023.

Kids Definition

booster shot

: an extra dose of an immunizing agent given to maintain or restore the effects of previously established immunity

Medical Definition

booster shot

: a supplementary dose of an immunizing agent administered as an injection
… the state is requiring older children to have additional booster shots for measles, mumps and rubella.Ann Schrader, The Denver Post
see booster, booster dose

More from Merriam-Webster on booster shot

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