Apparently 30% of cases of the common cold are cause by coronavirus. And the worrying thing is that the immunity we acquire for those is only temporary.
At this point, I think it's just appropriate to say "we don't know yet". This is a new virus, and not much is known about it yet.
And that is why drug development needs to go parallel with a vaccine. If a vaccine fails, we can fall back to drugs to prevent people from going into ICUs (hopefully).