What happens when one gets bitten by vampire?What happens when one gets bitten by vampire?
If the Vampire injects the venom, then you become one.
You die
To become a vampire is a a bit of a delicate process. It take repeated bitings and a gentle, protracted death to enable the contagion to effect the change. As Count Dracula performed on Lucy Westenra (Dracula) or Lestat performed on Louis (Interview with a Vampire). Inductions as depicted in Innocent Blood are ridiculous in the extreme.
Any person bitten by a vampire can recover. A single bite is nothing, hardly noticeable in fact. Lucy Westenra was saved three times by the intervention of Dr. Van Helsing - it was only by constant interference by the count that she died and was inducted. In fact if you are bitten repeatedly and don't die within the first few weeks then you become immune to the induction. Such is the condition of many thralls and minions of vampires.
Most induction are malformed. Count Orlock (Nosferatu) being only a medial example, gross deformities are more common than otherwise. Most people on becoming vampires destroy themselves as they are incapable of reconciling themselves with what they have become.
Werewolfs
Folk beliefs section of Wikipedia entry about Werewolfs gives more details about the common beliefs for how one becomes a werewolf, what vulnerabilities do those have, etc.