there is no virus ---- your civs get converted into rebellious units or xenos units according to the random card you draw at the beginning of the game to represent your threat in your sector of space. and due to the particular threat maybe one corresponding technology would be useless against them.
the re-theme in this case would allow those who dont necessarily choose to play a zombie game, actually play this game and find out how wonderful it is
i only bought it because a friend of mine who will have nothing to do with zombie games, was forced to play with his friends or drive back across town to go home and found that this game is unlike his expectations --- when he told me he liked it and would not only play it again but would buy it -- I was sold, and since then (3 weeks) it is the only game i have played
I could easily see something similar for 40K. Nations would instead be planets in a sector. The zed threat most likely would come from Tyrannid, Necron, or Chaos out of a sudden warp storm.
