Welcome to Gaia! ::

It deppends how you see it really...

Vampirism nowadays can be defined as a disease, if so, you don't turn into a Vampire, you just get "Sick", there are special skin conditions that make your skin react with the sun, also som ocular conditions that make your eyes intolerant to sunlight, ever seen people wearing shades, in spite it's cloudy or nearly night time? Albino people have their skin very delicate, so they can't spen't much time under sunlight. The thirst can be explained scientifically too, Vampiric Blood does not have hemoglobine, which is important for a system to be supported, therefore, Vampires have to get it from somewhere. There are several diseases that affect directly your blood, there are people who need to receive blood transfusions a couple of times a day, or they could die.

Romantically, I support both Anne Rice and White Wolf's approach to this. The classic Vampire just bites you, drains your blood and you're automatically turned into Vampire. If this was the case, the world would be packed with Vampires, seeing how when you have the need to feed, you sire another Vampire. Anne Rice and White Wolf establish that it is required to bite, drain blood from the victim, and then feed the victim with your own Vampiric blood, the physical body dies, and after a few minutes, a Vampire is born.

What happens if you don't drain the blood from the Victim, but feed it with your Vampiric Blood while alive? A Ghoul, or if you want a more general definition, a Servant is born, that Servant is still alive, breathing, being able to eat and drink, but have heightened senses, enhanced speed, fortitud and strength, after a few months (3-4) the effects disappear and the Servant can return to his condition of human until being fed with Vampiric Blood again.

This past approach comes from White Wolf as well, and if you have watched Interview With A Vampire, remember how Lestat created Louis, and how they sired Claudia too,