I'm looking for ideas for a highly contagious airborne biological weapon (virus, bacteria, other) that would kill its host in a matter of days to a week or so, but that, once all infected hosts are dead, would become inert after a while (perhaps a couple months) so that the air and the corpses no longer can spread the thing.

Details not required really, just is such a thing feasible/believable? Would it be called a virus or some other term?

  • $\begingroup$ the story takes place aboard a space ship. It will need to be quarantined for a while, but then accessible later $\endgroup$
    – ken
    Sep 11, 2018 at 20:09
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    $\begingroup$ This is perfectly natural and not exceptional in the least. All viruses and all bacteria are like this; if all the hosts die, then the viruses or bacteria will eventually become inoffensive. How long it takes for them to become inert depends on the specific species or strain, and on the specific conditions. For example, influenza viruses die quite quickly if exposed to air, survive several hours in mucus, and up to several weeks in faeces. $\endgroup$
    – AlexP
    Sep 11, 2018 at 20:17
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    $\begingroup$ What you want is a poisonous gas. $\endgroup$ Sep 11, 2018 at 20:19
  • $\begingroup$ The movie Outbreak included a virus like this. I'd assume that it's realistic. Might be worth a watch, as research. (I enjoyed it!) $\endgroup$ Sep 11, 2018 at 23:33

1 Answer 1


There was a very similar question recently (past few months), but I cannot find it.

If virus kills literally everybody, and it cannot survive outside the human body, then it will be gone once all the bodies are gone (or become too cold/rotten to sustain the virus). The spaceship with limited crew and no eco-system will work quite well. Burn the bodies along with all organic matter and the contents of the living quarters, then sterilize the ship with fire/acid/UV, and you are good to go.

If even a few people survive, they will continue carrying the virus (even though they themselves are immune to it). They will infect any new people who were not initially exposed. As an example, Native Americans died by the millions due to plague and smallpox viruses that European colonists brought with them.

  • $\begingroup$ Viruses cannot survive indefinitely outside a host. Some viruses will die quickly if exposed to oxygen, some will last longer, some will find a protective environment (e.g., a thin film of water), but in the end they will all die after a suitable amount of time. $\endgroup$
    – AlexP
    Sep 11, 2018 at 20:25
  • $\begingroup$ Small point, but it was smallpox, not chickenpox, that took out a staggeringly large number of Native Americans. $\endgroup$
    – jdunlop
    Sep 11, 2018 at 23:20
  • $\begingroup$ Another small point: viruses don't technically die, because they're not alive; they can't reproduce on their own. But as @AlexP wrote, they cannot survive in certain conditions. That means they are no longer virulent / active / dangerous. $\endgroup$ Sep 11, 2018 at 23:36

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