80% need no treatment.
15-20% get hospitalized, of those about 10% need ventilation.
As far as drugs, there have been a bunch of different antiviral drugs that claim to help but nothing seems to really be working.
It really depends on age though. For people 70+ this is very much a life threatening illness. For children, it seems less severe than the flu. A lot of question about how much long term damage the virus does to different organs.