Continuing Vaccination Dose That Renews Immunity

This page is the CodyCross answer for the clue below from Performing Arts, Group 891, Puzzle 3 (Ropes and Pulleys).

Question is: Continuing Vaccination Dose That Renews Immunity

and the answer is: BOOSTER

Word Meaning:

BOOSTER — Something that boosts.

Definitions from Wiktionary.