Welcome to Humor Nation. It felt like electricity running through my body, it felt like millions of stars exploding in the mind all at once, it was amazing. These are the words of Camille describing what it is like to be a vampire. Vampires are reanimated human corpses that are occupied by the spirits of the deceased and they look like a living person. They survive by feeding on human blood. They have different kinds of abilities and powers.
A human being who has consumed the blood of a vampire in any way, whether by being injected by it or drinking it, or having the blood of a vampire poured on their open wound, and died with having the blood in their system would transform into a vampire. But that doesn’t make one fully a vampire, in order to complete the transition the person must consume human blood within a period of 24 hours, or else the person will die.
The main component of a vampire diet is blood, a vampire can consume any kind of blood: animal, human, or vampire. The reason vampires crave blood more than anything else is because of the blood ingredient used by Esther in her immortality spell to create the original vampires.