booster dose vs booster shot

booster dose and booster shot both are nouns.

Word	Noun	Adjective	Verb	Adverb
booster dose	Yes	No	No	No
booster shot	Yes	No	No	No

As nouns, booster dose and booster shot are synonyms defined as:

booster dose and booster shot: an additional dose that makes sure the first dose was effective

Other synonyms of booster dose include booster, recall dose.

booster dose (noun)	booster shot (noun)
an additional dose that makes sure the first dose was effective	an additional dose that makes sure the first dose was effective