Operation: Man kind. guide line

Well its One an a half year after the human. Covenant war operation: Savior was temporary shut down do to..... a plague the story follows. Cap. Hunter 038 and a couple Orbital Drop Shock Troopers at the beginning 038 i waiting by a mongoose for a new recruit which is a civilian volunteer. And most of the civilians are in underground bunker that seals the plague. From the civilians guarded by 3 Spartans 4 ODSTs and 10 Ex thugs thats what stands between destruction and humanity well that and the out posts stationed between the bunkers all over the world

so thats just the basic info

Sounds like the flood.

its kind like that except this started on earth and its more of a thing in the air instead of a bunch of zombies and the infection makes some sort of suit kinda like armor making them stronger and their smarter then flood