4 of them are FDA approved. Which if the testing kits did the 4 studies use?
In a month we will know a ton more. Regardless, the high end estimates, nation-wide, are 10% or less of the population having had this. Far from "a good chunk".
I don't know what September will bring. If the rest of society is still practicing social distancing, and all indications are that they will be, I don't see stadium crowds happening. Not until we have real heard immunity.