booster dose

noun

1. a supplementary injection of a vaccine given to maintain the immunization provided by an earlier dose

Example Sentences

Eligible groups were offered two main doses as a minimum, plus a booster dose, with additional boosters for more vulnerable groups later on in the pandemic.

From BBC

And California officials require a booster dose for students entering seventh grade.

From Los Angeles Times

Similarly, if you qualify but missed an earlier booster dose, you can have another jab this spring to catch up.

From BBC

Federal health officials say U.S. adults 65 and older who got a shot of the updated COVID-19 vaccine in the fall should get a booster dose now, if at least four months have passed.

From Los Angeles Times

The FDA did allow seniors and others at high risk to get an extra booster dose last spring.

From Seattle Times