Doesn’t the first wave have to end for there to be a second?
The first wave never really goes away. But it calms down.
The worry about any second wave is a mutation.
The most famous second wave was the Spanish Flu. The first wave was in the late spring of 1918. It died down pretty quickly. It came back with a vengeance around Labor Day.
That wave killed a whole bunch of younger-middle aged people.
I am not saying that is going to happen. Just saying it could, and it could appear different.