Check out the posts by monarch71 in this thread, it seems pretty convincing to me.
It doesn't matter if a virus can make you a mindless drone, bringing back corpses on the otherhand is an entirely different story. You should go and research what happens after you die and how fast you really decay.
ZOMBIES ARE IMPOSSIBLE!!!
Now something like 28 days later where all the people were still alive and infected with a virus that made them go crazy is more plausible that bringing a corpse back to life.