User blog comment:Almiralovestwilight/What if JACOB is turned into a vampire?/@comment-100.36.252.204-20151109045500

Seriously it's so obvious. Jacobs heart will fail because he has werewolf blood inside of him and werewolf blood and vampire venom wouldn't go so well together. Jacob was born a werewolf and being turned wouldn't help him survive. Like carisle said ther are some symptoms that even venom can't overcome.