Z-Virus

The Z-Virus was a infectious disease of unknown origins that affected numerous worlds. It infects the populace, turning them into ravenous zombies. The virus only affects living matter though, and not the long deceased.

History
No one knows where the Z-Virus hailed from only that it was brought to the worlds of the Milky Way by meteors. Inhabitants of these worlds where these meteors landed would be infected with the gelatinous compound associated with these rocks. The first newly infected would turn into ravenous, mindless zombies, with an innate need to spread the disease. This virus destroyed numerous worlds and civilizations. However a cure was discovered by the Vordi, who later led a coalition of survivors of affected worlds to combat the virus.

The cure was developed and was slated to be used on Earth where a Z-Virus outbreak had recently taken place.

Source

 * Aliens vs Zombies 001