There seems to be a connection between the vampire mythology and the plagues which swept across Europe in earlier times.
People need to explain away their fears.
Right now Republicans are explaining away fears by linking Obama to Marxism and socialism and by extension presumably communism although the three are not quite equal. But who cares about details...
Reuters: "Vampire" unearthed in Venice plague grave
The succession of plagues which ravaged Europe between 1300 and 1700 fostered the belief in vampires, mainly because the decomposition of corpses was not well understood, Borrini said.
Gravediggers reopening mass graves would sometimes come across bodies bloated by gas, with hair still growing, and blood seeping from their mouths and believe them to be still alive.