I'm guessing you don't need to be bitten to turn to a walker ii must be like a cold virus where you are just infected.
No, you do not need to be bitten to turn into a walker. If a human is bitten or scratched while alive, they eventually turn into a walker. If a human is stabbed, dies of natural causes, or is shot in the heart, they die and come back as a walker.
The only way, if a human is killed, that they do not come back or turn into a walker is if they are shot or smashed in the head. Must be that if the brain is destroyed then they cannot come back as or turn into a walker.
Shane was stabbed in the stomach/chest. The prisoner's neck was snapped. That is why they were able to come back as walkers.
C'mon people...it's Zombie 101!
Some food for thought......What happens if Laurie were to have a miscarriage? Would the baby turn into a zombie while inside of her!
WHAT A GREAT SHOW! SUCH PHENOMENAL WRITING!