I’ve heard of actual vampirism as a psychological condition. Take that Turkish countess ummm Elizabeth Bathory. I guess the time she wouldn’t be a vampire is when she wasn’t sucking and bathing in blood. Sorry to take your question to literally. *Sips tomato juice box*
Are you talking about the subculture of people who need annual consumption of blood/”energy” or else they get sick, or the beings of myth? Myth, I think their humanity, if they ever were human as most “vampires” were born as human-devouring creatures, would be so far gone that they would simply view humans as food and nothing more. That is, assuming, they were not the reanimated corpse kind, in which case, they would be more zombie like than anything, just searching for blood instead of brains. XD
I used to spend a lot of time reading about vampires. The concept of a vegan vampire is extremely new, especially considering the fact that they were soulless monsters and demons. More animal than human.
I like to use Anne Rice’s version of vampires, as the aristocratic nobles who see themselves as ancient, undying royalty and humans as less than as symbols of how humans often are with animals.