The zombies are a distraction/trial run for an invasion by aliens that don't suck.
Or...a bunch of annoying teens are at high school in the US, when a zombie outbreak occurs, only the zombies are in Africa and so they don't care. Only, then the media gets bored with saying that CERN is going to kill us all, and for two weeks they pretend zombies will kill them all. Everyone at the high school panics and the token black character is murdered cause he's, like, African and so he must be zombie (if the token black character is a sassy black chick, then she's murder for being, like, half-African, cause we can't have black women who are too black).
Then the media says it's hedgehog flu that will kill everyone, and they all forget about zombies and start being afraid of hedgehogs.
Also, there's gratuitious sex for no reason, I guess.