The Virus

In the world of Last Stand, the Virus is the "Main Antagonist".

Origin and how it spread
The Virus came somewhere from outside of America. The first case of infection is a man named Con Johnson who entered the Union City Hospital. He died when they took him to a Autopsy. Days later, the first witnessed reanimation occured, and Con Johnson bit a Doctor/Nurse/Animal, and thus, the Virus spread. It didn't take long before whole Union City and all other Towns were Infected.

The Virus, how it spreads and how to prevent (?)
The Virus spreads by exchange of bodily fluids with a Zombie. If the Zombie bites a Human-Being or a Animal (though, only Dogs have been known to be affected). Even if the Zombie dies, and the affected Limb gets cut off, the Virus will STILL live in the Host. The Virus has been known to be aggresive even after losing fatal organs (all but the Brain), killing the Host and then reanimating it. It cant be prevented, but keeping Distance from Zombies can help.

the Zombies can be killed by the following: No Cure has been found yet.
 * Heavy Head Trauma
 * Destroying the Hosts Brain, or
 * Putting enough Bullets into the Zombie.