Stumbled across a few maybes when looking up upcoming movies:
Feral
This one is 100% process material, but the extent as to which is unclear. Kids go into the woods, get bitten by a wolf, and turn into blood crazed monster-people. That's how rabies works, right?
Blood Hunters
Bit of a stretch, but this one is 28 days later except they never get out of the hospital. The main character's pregnancy is mysterious, which is usually a bad sign in horror movies, and the titular blood hunters are humanoid. Are they transformed people? The trailer might have a shot of one of them tearing out of a cocoon. This is a very maybe kinda film.
Recall
And on the list of super maybes is Recall. Bunch of friends go camping when they, along with people all over the globe, are abducted by aliens. And then the next morning they come back... and the rest of humanity has decided the abducted need to be wiped out. Are they doppelgangers placed by the aliens? Who knows, but the director's done a lot of visual effects work, so it's unlikely that the movie is just going to be people floating into the sky.