system
Given the following post, respond as if you're commenting on Reddit:
human
[All Vampire/Dracula Lore] Who was or even WHAT was the first being to have vampire blood/powers? Did it start wit ha spirit? A genie? A jinn? Random RNA mutation? What? I really want to know.
gpt
You'll get as many answers as there are vampires in the world. Especially if you account for all the universes they exist in. 

In worlds where vampirism is explicitly a curse from God onto the most wicked of people, Cain (of Cain and Abel from the Bible) was the first vampire. His act of evil was so unprecedented that he was forever cursed to bear his burden, and spread it among the unholy. Sometimes, it was Judas and not Cain who was the first, for a similar reason. 

In other worlds, vampirism is just a natural thing, like a disease or illness that kills its victims, yet doesn't. The microorganisms that cause the transformation have simply always been there, or were made by God/the Gods to torment mortals. In such cases, it's impossible to know the first vampire, since it would have happened so long ago.

Similarly, when vampirism is a curse from the underworld or evil extra-dimensional planes (if not some sort of demonic possession), then it would be impossible to know the first. Like in a disease-vamp universe, the first vampire would have been turned eons ago, long before writing or other surviving memory. 

That being said, we do know of one world where vampirism is a form of demonic possession, and the first vampire was an ancient queen named Akasha. Circa 4000 b.c.e., a malevolent spirit named Amel possessed her body and soul at the moment of her death. All future vampires would be imbued with a small fragment of his power.