This song was written for the Queen of the Damned soundtrack, but it could truly have many meanings. It could be about vampires, yes, or a person who is in a position that makes them feel as if they are a monster. Or someone who has been called an outcast, but realizes "I can not be forsaken, for I am not the only one."
However, it is most plausibly about vampires. And this is but one of the many variants of this song.