User blog comment:Twilightslastgleaming/What If: Jacob Black-Cullen/@comment-1712062-20100323010749

Vampire venom is poisonous for shape-shifters; that is why Renesmee can play around biting Jacob since she is not venomous like other htbrids such as Nahuel & I don´t think he is always 100% human cause do you remember when the gorgeous female vampire entered to the Quileute territories to take revenge of hus deceased mate,Quileute children said she smelled so bad that made their noses hurt. So I don´t think a shape-shifter could be turned to vampire, not even if he has not changed to a wolf.