What was the cause of the virus that turned dead people into zombies? For example, was it after a nuclear blast or explosion? Was the virus in food or water? Or did the virus surface because of a post apocalyptic occurrence?

  • "post apocalyptic occurrence" -- can you be more specific as to what this means? Nov 29, 2014 at 22:45

1 Answer 1


This has not been answered in the show.

In Series 1 Episode 6, Rick and his group

reach a Center for Disease Control facility

where they meet Dr Edwin Jenner, a scientist who has been trying to understand the zombie virus. Jenner has more scientific knowledge than any other character in the series so far, and has closely studied the virus; but he doesn't mention anything about its origins, probably because he doesn't know.

However, we can rule out a "nuclear blast or explosion" as the cause of the plague. A large-scale nuclear detonation is impossible to conceal and would be international news, but none of the characters has ever mentioned such an event.

  • I doubt any of the survivors are equipped to test for radioactive nucleotides in the atmosphere. While I doubt the Walking Dead apocalypse has anything to do with nukes, assuming nuclear war was swiftly followed by a plague and societal collapse, it is entirely conceivable for people to be unaware of it. Recall the mystery nuke in World War Z, for example. Nov 30, 2014 at 0:32
  • @JamesSheridan: Yes, but the mystery nuke in WWZ was detonated after the zombie plague had taken hold. If the origin of the plague was related to a nuclear event, that event must have occurred while technological civilization was still functioning, and government agencies, news media, etc. were around to report on it. Nov 30, 2014 at 0:38
  • Those sources may not have lasted very long. Nov 30, 2014 at 6:53

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