Get to the crux of cardiovascular hiccup pertinently, to prevent disease (7)
I believe the answer is:
vaccine
'disease' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for vaccine that I've seen before include "Antibody stimulator" , "Immunity stimulant" , "Immunity provider" , "Preparation used for inoculation" , "Vice can create protection against disease" .)