This could be a perfectly fine film, the thing is that plot isn’t really that important. Pacing and emotional stakes are way more important. Add some characters and make the audience give a shit about them. Maybe also make the flu a metaphor for something, then you have a film.
“So I made a time machine and went back in time, gave them the flu and wiped out the entire human species.” The End.
I guess when you put it like that, it sounds kinda stupid.
A more creative person than me might be able to do something with it
This could be a perfectly fine film, the thing is that plot isn’t really that important. Pacing and emotional stakes are way more important. Add some characters and make the audience give a shit about them. Maybe also make the flu a metaphor for something, then you have a film.