Vampires do not exist. The whole idea of the vampire came from the lack of understanding of normal decay processes following death during the Middle Ages. For centuries vampires were hated and feared. Then along came Hollywood movies, fantasy novels, and role-playing games and suddenly everyone wants to be a vampire. Well it isn't going to happen.
And as vampires do not exist then in the same way vampire-hybrids do not exist. They are straight out of fantasy.