Sutek said:
Actual vampire and lycanthrope lore most likely grew out of an epidemic of rabies that took place in central Europe about the time of Vlad the impaler. Odd conincidence, and I could be wrong about the timing, but think about the typical "weaknesses" of vamires: sensitive to sunlight, ravenous, refusal to drink or eat or even to go near running water.
What is your source for that? According to Jan L. Perkowski (one of the foremost researchers on Slavic vampirism), the idea of the modern vampire took root in the ninth century because of a cultural confrontation in the Balkans between pre-Christian pagan, Christian, and Bogomilism beliefs. (Perkowski, Jan L.,
The Darkling: A Treatise on Slavic Vampirism. Columbus, OH: Slavica Publishers, 1989. 174 pp)
Many researchers attribute many of the Eastern European beliefs in vampires to have its origins in India, where it was brought to Europe by the Roma (Gypsies). (Melton, J. Gordon,
The Vampire Book. Canton, MI: Visible Ink Press, 1999.) I believe Montague Summers also agreed with this view, but it has been a while since I have read his work (
Vampires: His Kith and Kin and others), so I could be mistaken.
Vlad the Impaler ruled in the 15th Century, but the big Vampire Scare of Europe didn't occur until the 17th Century (the Arnold Paul incident) (Melton, J. Gordon,
The Vampire Book. Canton, MI: Visible Ink Press, 1999.)
A lot of folklore vampire lore rose from problems with people not adapting to the community - vampires often were products of irregularities in community life (again, see Perkowski's research).
The rabies theory also doesn't explain the vampires of ancient peoples (Egypt, Greece, Rome, et. al.)
Our modern vampire is based on the Slavic model, but highly modified by cinema and our changing culture. In cinema, at least, vampires have moved through a malignant cycle (1931-1948), an erotic cycle (1597-1985) and a sympathetic cycle (1987 to present) (Kane, Tim.
The Changing Vampire of Film and Television: A Critical Study of the Growth of a Genre. Jefferson, NC: McFarland & Company. 2006).
The running water weakness is actually unique to the novel
Dracula (although Van Helsing attributes it to all vampires) and does not appear among folkloric vampires, according to Montague Summers, Paul Barber, and Perkowski.
The idea of staking a vampire predates the use of coffins, according to Paul Barber, and was a means of keeping the vampire attached to the grave (Barber, Paul.
Vampires, Burial and Death: Folklore and Reality. New Haven, CT: Yale University Press, 1988)