Using Blood Living in Science Fiction and Science Fiction

The idea of a pathogen making everyone sick is a bit of a cliche but it's also so believable that it would almost not make sense to never feature this. This sort of thing is also true in science fiction when characters are planet hopping because the germs from one planet are not existence on the other generally unless they've already been introduced. Rather than gloss over this kind of thing we probably want to quickly show it or even in something like a book where the number of days being passed is irrelevant as long as someone has been inoculated against these things. We call it artistic license just be aware that it's not that believable but people will accept it.