I have been tracking where the origin of this vampirism comes from and I have come to a few startling discoveries, most of these vampires are new people. They were citizens of the cities or recent out of towners they were not vampires when they got here and several symptoms have been spotted.
They fear the sun.
They are not repulsed by garlic.
They cant get into some buildings... I have yet to figure out which they cannot enter.
Most interesting about the third is that this does not go both ways. I have spent four evenings in the following vampires apartment without issue.
