Not sure what you're talking about. It is already well-known in my FC that I'm a vampire!

On a more semi-serious note, werewolves and vampires are not races; lycanthropy and vampirism are typically known as sicknesses wherein the original host or 'true/head werewolf or vampire is shrouded in mystery. I bring this up because SE is a bit known for digging a little deep into the origins of many concepts they use in their games, and if either were introduced into the game, I am guessing it would be in some form of illness that an NPC is suffering from, or instead of a new race, they could possibly be new jobs. The latter of which I would gravitate to like a moth to the flame.