I'd like to send my protagonist permanently into the near-ish future. I suspect that something as simple as the common cold could be deadly to my protagonist once we get a little further along.

I am looking for a rule of thumb that there might be, in science or hard science-fiction. Setting aside the following variables:

  • Yes, I know everyone's body is different, I haven't been sick for more than a decade while I have friends who are sick every month. I'm just looking for a rule of thumb.
  • Yes, it's fine if there's been an advance in medicine, but this is about contraction (and, if there's a rule of thumb used in fiction) of common airborne diseases as we know them today, such as the cold. Assume our daily, urban lives are as they are in the West, just with near-future technological advancement.
  • My protagonist came from today and I want her to travel as far into near-future (100 to 200 years) in the same, progressing country, that wouldn't create a quick contraction of a virus or bacteria that could cause major complications.

To avoid this from being too broad: What's the best rule of thumb in worldbuilding/storytelling or historical precedent for how far a person today might travel without being seriously compromised by a common, airborne disease; without imagining completely new diseases.

  • $\begingroup$ Is there some reason to believe she would get extra sick? Sure, she'd be exposed to a bunch of newer strains of viruses, but I don't see why she'd have any more trouble with them than just heading across the world today. We don't survive "common cold" viruses because of when we were born, but because they're not particularly nasty. $\endgroup$
    – MichaelS
    Commented Mar 3, 2016 at 8:16
  • $\begingroup$ @MichaelS - I don't know anything about biology, so I wanted to ask the worldbuliders if there's a precedent / rule of thumb for bringing someone not exposed to a "place" (time actually) where they've not been exposed. Certainly the Americas have precedent for exposing a population that had once been isolated. $\endgroup$
    – Mikey
    Commented Mar 3, 2016 at 8:29
  • 1
    $\begingroup$ Those diseases were generally pretty dangerous to the Europeans who brought them. Certainly not "common cold" stuff. My hunch is she'd be more dangerous to them than they to her, simply because she might carry diseases they thought extinct and had quit vaccinating for. On that note, can we expect her to receive normal (for the future) vaccinations on arrival, or is she identity-less and trying to remain hidden? $\endgroup$
    – MichaelS
    Commented Mar 3, 2016 at 8:36
  • $\begingroup$ @MichaelS - another good point you raise is people travel all over the world daily with hardly a single problem. Anecdotally a few catch a cold from being on the plane, etc. but most problems are minor. The larger are rare. $\endgroup$
    – Mikey
    Commented Mar 4, 2016 at 4:36
  • $\begingroup$ Actually, it's a very question, but there isn't any clean rule of thumb. Yes, they very well might be tuning around with antibodies that mean they find offshoots of their stain of super flu that wiped out 80% of humanity only make them ill now, but they might be far enough removed from avian swine flu that it's relatives start another epidemic. The threat flows both ways. $\endgroup$
    – The Nate
    Commented Mar 7, 2016 at 5:37

1 Answer 1


You can get a stinking cold just by being projected to next year.

As a general rule, your traveler from the past is going to be taking long cured/vaccinated diseases to the future rather than getting new ones by traveling to the future.

That wouldn't have been true during the great age of exploration through the 15th to 19th centuries mind you. During that period the western explorers were picking up all sorts of fascinating new diseases from across the world.

In terms of colds, people tend to have a localised immunity. As people travel across the world (especially freshers at University) they take a home version with them and spread it around while picking up a local version at the college.

Imagine if you will, a traveler from 300 years ago landing in our time. (I know this is a greater time than you're looking at but it's a good point in history for this.) This person is going to turn up with a few virus variants that we haven't seen for a while and will catch a few from us, but he could turn up with any of TB, Bubonic Plague or even Smallpox! To us these diseases are largely consigned to history or standard vaccination and treatment schemes but to them they were a part of life.

What would your traveler be taking with him that the people of the future have consigned to history? Measles? Chicken pox? Polio? Things that should have been forgotten are now showing up because he traveled to the future.


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