It's easy to look at the vampires as a metaphor for any feared or misunderstood group. It's also easy to look at them as a metaphor for a shadow organization that says one thing and has a completely different agenda on their mind, and anybody who gets in their way, they just get rid of them. Does that sound familiar?
In my own life, I think legends of supernatural, mythic things are really just a manifestation of the collective unconscious. So I don't really get freaked out. I mean certainly, you read about things people did to each other in the pursuit of some mystical or occult goal, and it's horrifying. But that's just human nature.