My question is, of these asymptomatic people that do go on to have symptoms...how many are so severe that they would have likely missed work or gone to a doctor? I think that is important too. How do we know if a bunch of people have had it, but had such minor symptoms that they just went on about their day? I had a spout of shortness of breath around late Feb - early March, I just chalked it up as allergies. Maybe it was? I have no idea, but how many people that get COVID19 have similar situations where symptoms are so mild they just think it's nothing. That seems important when we look back in time where people weren't on edge and on the look out for any type of symptom. Of course asymptomatic people are going to show symptoms, but does that mean they would have reported it were they not told by a doctor to report anything out of ordinary?
We need widespread home antibody tests. I had a bad chest cold for a month recently, probably just a cold but I sure wish I knew for sure. If I found that I have antibodies I would try to volunteer to help in the fight and donate plasma. It would completely change my behavior, but I may never know unless I get sick as a dog with usual symptoms.