If you’re vaping something that contains PG (Propylene Glycol is used to create throat hit that cigarrette smokers crave.) When vaping the PG does end up coating your throat, depending on the person it can be irritating and some people are actually allergic to PG. Try drinking water and staying hydrated while you vape, as dehydration contributes to the sore throat/raspy voice.
One cause may be due to the PG additive. Propylene glycol (PG) is a synthetic base found in most e-liquid products. It is often used, because it does not have a flavor like natural vegetable glycerin does, another base. PG is an alcohol (dehydrating) which may cause the back of your throat to dry out as it coats your vocal cords. This may result in hoarseness or a sore throat.
Another reason may be due to the flavors that are added to the e-liquid. Anything that can be irritating to the throat can cause inflammation of the vocal cords causing hoarseness. Most people find that if they drink more water or rinse their throat with mouthwash before bed that this symptom resolves.
In addition, too high of vaped heat can cause vocal cord damage too, so make sure that is not the problem.