Yes, VACCINE is a Scrabble word!

Letter values in Scrabble US: V 4, A 1, C 3, C 3, I 1, N 1, E 1.

Is it a valid word?

VACCINE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

immunogen consisting of a suspension of weakened or dead pathogenic cells injected in order to stimulate the production of antibodies

Not playable in Scrabble US: VACCINUM.