I've only seen one serology study, the one out of Stanford for Santa Clara County. At the time of the test, that county of 1,928,000 million people only had 960 positive COVID-19 cases. So, 0.0004973% of the population are confirmed positives. The headline in the Mercury Sun News regarding the serology was something like, "positive cases are 50 to 85 times higher than what we know". Which sounds amazing right....wow, if that many people have already had it....then we may be closer to getting this all over with.
However, this takes us back to math. Multiply our confirmed positive number by 50, and we get 2.4%. By 85, we get 4.2%. So, instead of just 960 people being positive, Santa Clara County, with a population of just under 2 million people, likely has 46,000 to 81,000 positive cases, which is still....just 2.4 to 4.2%.
But, Santa Clara County, locked down very early, before they had a lot of cases. A lot of really smart people live there. Again, keeping with my "smart people do best in a pandemic" theme. They locked down almost a full week before most of the rest of the country. And so yes, we may have a higher percentage of positives in areas that developed larger outbreaks. I've seen estimates as high at 10%. So if 10% of us have had it in the country, great, that's 33 million people. And so 297 million of us have not. We've got a long way to go.
We're going to be going through this, and living with this virus for a long time. I'm not sure most Americans fully grasp that fact yet.