But after 33 years of vampire hunting, quite a few. The Highgate Vampire are photos of a vampire soon after exorcism, in the stages of decomposition. These have been transmitted on TV several times in the 1990s. I employ Christian symbols, but without the faith they would be ineffectual. People do not become angels.
People are people who pass on.
Vampires are intrinsically demonic, and possess and contaminate a person who after death doesn't lie quietly in the grave. Immortal is not a word that I'd employ, but I understand what you mean. Vampires cannot die, but must go on. The vampire bat is an animal, which lives off the blood of cattle, and occasionally sleeping humans. Vampires cannot be killed.