booster shot


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

called also booster, booster dose

Examples of booster shot in a Sentence

He had to get two booster shots at his latest checkup.
Recent Examples on the Web The booster shot is meant to top-up immunity for people most vulnerable to infection before a new round of COVID vaccines roll out this fall. Claire Bugos, Verywell Health, 11 Mar. 2024 Now, those over 65 should also receive a second booster shot under the new recommendation. Irene Wright, Miami Herald, 29 Feb. 2024 Research shows that people who got the latest booster shot were 54% less likely to be infected with Covid this winter. Erika Edwards, NBC News, 15 Feb. 2024 About 17 percent of the U.S. population has received the new, bivalent booster shot, according to the Centers for Disease Control and Prevention. Danny Nguyen, Washington Post, 29 Dec. 2023 In the discussion, hosted by DeSantis, Florida’s surgeon general, Dr. Joseph Ladapo, told viewers not to worry about getting infected with COVID and advised Florida residents 65 and under to forgo the booster shot. Alexa Mikhail, Fortune Well, 21 Sep. 2023 Fewer than a quarter of Chicagoans received the bivalent booster shot offered last fall, CDPH data shows. Jake Sheridan, Chicago Tribune, 15 Sep. 2023 The study analyzed data from 303 people who received the mRNA vaccine as well as a booster shot. Leada Gore |, al, 22 Aug. 2023 Unlike the last booster shot, which was approved around this time last year and protected people against two strains of the virus, the new mRNA vaccine only targets one strain — the omicron variant, XBB.1.5. Angela Roberts, Baltimore Sun, 15 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'booster shot.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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 20 Apr. 2024.

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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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