I still do not know how it started, but it came quickly, burned through a majority of the world’s population, and then flickered out with the advent of the vaccine. The time between dying and re-animation varied widely, resulting in many attacks within families. You know, a family member would die, the family would begin to mourn and then the relative would come back to life, and attack the other members of the family. As the virus spread, either by transmission on contact or consumption, its origins were lost in the mayhem. In then end only a cure was desired, its origin did not matter. Only the end of the madness could be conceived.
Yes, I have been vaccinated, but sometimes I wonder if I should have chosen not to do so. How could the researchers desperate for a miracle and when they found it, have known it would have such a drastic side effect? Sure the plague the LD001 had caused was eliminated, but engineering such a cure gave the complete opposite effect. Instead of becoming infected, dying, reanimating and living again only to die shortly after, the vaccine made the uninfected immortal.
People would never die from old age. Granted one could still be killed, but never from a degradation of the human body over time. The savior from becoming one of the undead was to live forever from the vaccine.