Thanks for this interesting thread! I wanted to throw a detail out there into the discussion to see if this matters at all. What might be the significance within these thoughts of the way alcohol fends off the zombized attackers? I'm partial to the idea that what has saved Saul and Tanya has been their antibiotics, which might point more to a bacterial infection that is spread, primarily, through the blood (and maybe also through saliva). Perhaps in its earliest stages, it was airborne, also, which could be the connection to Radon Labs (more on that in a moment). Alcohol does kill most bacteria, and if this bacterial infection has some sort of sentient properties within a body, perhaps it sensed inherently that the alcohol, though not a complete threat to the body it was in, would not allow the bacteria to spread (and if ingested could harm part of the infection within the body in which it was living. Stronger antibiotics might help resist its spread within a body, such as Saul and Tanya. A question, though: does anyone know - could an antibiotic treatment also serve as a vaccination against future bacterial attacks? Or was Saul "immune" to the ground zero sight only because he was still on his IV drip?