XP vs. Vampire

True Blood the TV series on HBO tells the stories of a world where vampires and humans co-exist thanks to the invention of synthetic blood by the Japanese.  Overnight, the mythological creatures were able to  become mainstream everyday citizens.  I wonder how these folkloric tales started.

tales of these mischievous death causing creatures dates back way before the early 18th century when the legend was popularized in Europe.  Through out history there are many different descriptions of vampires and they all depends on the culture, though there are some similarities such as blood drinking and light fearing.

I wonder if all these tales are simply stories made up by people who are afraid of the unknown. Unknowns such as the rare autosomal recessive genetic disorder called Xeroderma pigmentosa where effected people cannot repair damages in their skin caused by UV light thus forced to live in darkness.  Vampires burst into flames when they are exposed to sunlight and XP causes unusually severe blistering sunburn even after very short sun exposure and eyes that are painfully sensitive to sunlight.  Ancient Vampires were described to have dark skin (instead of the pale skinned creatures we know now) and people effected by XP often develop irregular dark spots on the skin, solar keratoses, freckles, and spidery blood vessels.

I don't know why I couldn't just watch a show just for the sake of watching, instead my mind starts to race and all these questions comes to the surface.  What do you think about the idea that Vampires are just misunderstood people with XP during ancient times?