True Blood

I got hooked on this show last week. Caught the first 7 episodes on On Demand. I'm a little thrown off though on how they make vampires.

Sooki is immune to becoming a Vampire after drinking Bill's Blood that healed her. People are getting high with superhuman senses after a few drops of V blood.

But then in the flashback, it shows Bill becoming a Vampire after drinking Vampire Blood. Do Vampires now decide if their blood makes another person a Vampire or not?