Nerdluster Writes: In the world of comic books, movies and television there's a lot of different ways you can become a zombie. Once turned you're usually permanently dead but you still have plenty of choices as to what kind of shambling horror you'd like to become. Depending on which mythology you subscribe to the undead have key features that tend to separate them into two main categories: "Walkers" and "Runners". The undead in World War Z are definitely runners and their fatal disease is transmitted through saliva carried in a bite from an already infected host. Within 7 seconds of the initial infection the news host is dead and under the full control of the virus.