I am going to tentatively say yes, but it largely depends on the mechanics of that. All optional? No harm, no foul, continue on your way. If it is something mandatory, it will depend.
Vampires aren't that well integrated into fear, but their weaknesses can definitely make them disliked by other Sims. In the vampire heyday, close to launch, one hisser of mine found it impossible to have a social life beyond her vampiric nuclear family. Years later, I don't even try with her.
I get it, though. They're hardly terrifying when even the most evil vampire will voluntarily release a Sim from his/her grasp before the thirst bar is filled, and will then voluntarily wait to drink again even when so thirsty as to be confined to his/her dark form. I don't think they will allow us to kill a Sim with it, but they should. Plus, the hypnosis/influence cooldown makes it pretty useless as well. Then the vampiric night visits were gutted. Certainly nothing to be afraid of.
