What do you think the church is? They find they're "lost" prey in the "dark" subdue them with hypnosis and begin to siphon out what allows them to live- time and money- all the while benefiting from their victims slowly dying in there grasp.
They are and they aren't. They aren't real in the sense of how we see it in books or in TV. But there are such vampires that drink blood, but do nothing else of what we see in books. Someone studied the subject for many years, and came to the conclusion that vampires do exist, just not how we see it in the media.
Not like in TV, movies and books, no. However there are subcultures of people who enjoy pretending the lifestyle, living at night, drinking blood and even having fangs surgically implanted. There are also people who suffer from very rare sun allergies, the worst of which can cause them get severe burns and even kill them. These very rare but real allergies are likely where the vampire myths actually began in a more superstious and ignorant time.