This isn’t relevant to anyone who is likely to play in an ORE-based Vampire game, since the framework for character generation is deliberately constrained to generate vampires and only vampires. But to put a vampire in the context of generating a WT character, I’d probably go with the following to generate an archetype for a vampire:
Source: either Genetic, Life Force or (obviously) Paranormal. This depends on whether you view vampirism as a transmissable blood disease, a manefestation of the blood itself, or a supernatural creature that has to drink blood.
Permission: Super, or possibly Power Theme.
Intrinsics: This is where it gets interesting. Firstly, a whole load of Allergies to Sunlight, Holy symbols, Fire and the like (although Fire is already damaging, of course). You could treat the vampire’s thirst as an Allergy, reducing their Willpower when their blood gets low. These can be varied depending on clan weaknesses.
Next, there’s the Inhuman intrinsic flaw. This could selectively apply to some vampires, or could apply to all of them depending on whether they cause humans to instinctively react to a predator.
Finally you could consider No Base Will or Willpower. You’d need to call it something else to avoid confusion with vampire Willpower, but it would mean that vampires can only power their disciplines by stealing Willpower (or any vital force) from others.