The origins of the Wildfire Virus is one of the biggest mysteries of The Walking Dead that will likely go unsolved forever. The virus quickly became a pandemic by killing people and then reviving a small part of their brains, allowing them to rise as zombies (known as "walkers"). But who was the first person to be infected by the virus?
Source：https://www.cbr.com/who-was-patient-zero-walking-dead/
