Honestly, Deku would probably get the worst of it, since he has several powerful Quirks. He'd keep smashing whatever he touches with One For All, Dangersense would make him super irritable (because of the splitting headaches involved), Float would send him hovering a few feet off the ground every time he coughed, and every time he sneezes, Blackwhip would explode outwards, taking out the windows in whatever building he is in. It would also be an issue for him because he's such a workaholic, he'd actively try to continue training even when he can barely function, forcing his (also sick and miserable) friends to hold him back and convince him to rest.
