The old folk-tale vampires were quite different from their more modern counterparts. Originally vampires were said to feed on life energy alone. They would visit their victims at night and slowly drain them. The symptoms on the victim were weird behaviour and, of course, fatique. Vampires were rumoured to be hairy, smelly man-creatures, much like werewolves.
Then someone somewhere came to the conclusion that because the Bible says "blood is life", vampires must feed on blood. Vampire-lore adapted to that. Now, vampires had pale, leathery skin suitable for someone exceedingly anemic. If a buried corpse had bloated, crimson lips, hair- or beard-growth or no apparent signs of decay, it was easy to declare it as a vampire.
To seal a vampire's powers you had to quickly drain it of its blood - by decapitation or a stake through the heart. Many means were invented to keep the undead at bay. For example, garlic was introduced as repellant because vampires were believed to have enhanced senses, thus making them vulnerable to strong smells and sounds. The only real way to kill a vampire permanently was to burn its body.
Then along came Bram Stoker who made vampires seek for suave passion, not horny lust.
By the way, African vampires ate whole cows, Indian vampires children. One Indian vampire was like a leech as it sucked blood from a man's toe.
What this comes down to: don't make vampires just stupid old monsters who drink blood and don't die easily; Everybody I know hated Blade I & II