It's airborne blood, fresh and AB+ to be exact. Anyone in the cloud is pretty much covered in the stuff.
I'd imagine it's somewhat thicker and thus a lot less see trough. (Its why I left, not worth risking taking a stray bullet if I can't enjoy the show)
I assume that a vampire benefits from fresh human blood regardless off how it gets into their system. One might argue that since you both have exposed wounds the stuff can be directly absorbed into the bloodstream.

So by my logic: to vampire's that vaporizer is like the healing gun from the team fortress 2 medic. to a human it's terrifying but harmless.
Either way it completely ruins you good suit.