That is the fear. And that's why medical experts are horrified that Trump wants everyone out and about by Easter.
Because there's no immunity, there's no cure, there's to this point no real treatment so... why wouldn't this pop back up again in staggering numbers? It would be sheer dumb luck if it didn't, but if you're betting, you bet on Round Two of all of this.
And then we're talking more social distancing, more unnecessary infections, more deaths. You're almost certainly talking about no Fall sports, probably no baseball season at all (not even the late-start version MLB is toying with right now), nothing.
There's no legit reason to restart the country right now. And if we don't, tens of thousands of people will be killed for no reason.