Unfortunately, vampire apologists solved this problem decades ago, with vampires mostly just preying on humans, killing them, and only occasionally and deliberately not killing them so they would turn into a vampire.
Witness the Interview with a Vampire stuff.
Heck, there's a game, Vampire: The Masquerade: Bloodlines where your character starts off as an "illegally" (in vampire society) produced new vampire. The "sire" is executed for violating the law, and you are almost, too, but they have a change of heart.