booster shot

noun

: 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

Researchers suggest that getting a booster shot during the optimal period could offer a 3-to-4-fold increase in protection compared to other times of the year. —Fran Kritz, Verywell Health, 9 Dec. 2024

Parents, family members and caregivers who will be in close contact with babies younger than 1 year old should get a booster shot. —Dr. Shreya Doshi, Boston Herald, 8 Dec. 2024

Health experts suggest getting an annual booster shot to prevent these illnesses. —Marley Malenfant, Austin American-Statesman, 17 Sep. 2024

Key Takeaways There is no official recommendation for a summer COVID booster shot. —Korin Miller, Verywell Health, 5 June 2024

Word History

First Known Use

1944, in the meaning defined above

Kids Definition

booster shot

noun

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

Medical Definition

booster shot

noun

: 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