While I don’t deny that the virus would spread incredibly quickly if it was airborne, I really don’t think it would take hold that quickly if a fluid vector was required. Similar viruses such as HIV, Hep B or Hep C only spread as far as they do because they’re shared by sharing needles (which generally requires non-cannabalistic people involved) or by unprotected sex, which I seriously doubt anybody would have with a zombie. The I Am Legend method seemed the most likely, albeit improbable.

While I don't deny that the virus would spread incredibly quickly if it was airborne, I really don't think it would take hold that quickly if a fluid vector was required. Similar viruses such as HIV, Hep B or Hep C only spread as far as they do because they're shared by sharing needles (which generally requires non-cannabalistic people involved) or by unprotected sex, which I seriously doubt anybody would have with a zombie. The I Am Legend method seemed the most likely, albeit improbable.