I would have no objection to an optional toggle to turn Vampires off. That said, to date, the Gurus have said they're not implementing such toggles. I suppose anything is possible, but it seems unlikely at this point.
What they -have- done, and what I and others who bought this pack because we want vampires are afraid of, is to severely curtail NPC actions by the stated supernatural (IE Aliens). Most people who bought this pack want to play with vampires and have that fantasy element.
The best option, if you -really- hate vampires and/or fantasy and don't want them in your game at all is still: Don't buy the pack! Seriously, there's some cool stuff, but it's all very vampire/gothic-themed. I don't see how much of it is even going to fit in a so-called 'realistic/non-fantasy' game setting. Get used to the idea that not ALL content is going to be for ALL players and you may need to compromise on occasion -- we all have to. That's just life.