Do you need to aspirate subcutaneous in vaccine?

Anytime you insert a needle into someones body, unless it's in an autoinjector, to give them a medication of some sort, you need to aspirate for blood. That is an important key in giving vaccines because anytime there is blood, you've hit an artery or vein and the medication should not be injected. Especially in a SQ, if you see blood, you're definitely not doing it correctly. In a SQ, it's fatty tissue, separate from veins and arteries. Aspirating is a good thing!