Professor Hendrick Streeck, University of Bonn director of the Institute of Virology and Institute for HIV Research, did a reasonably large study in THE most infected area of Germany, at Gangelt, Heisberg.
He studied about 500 households with thousands of people. He did a lot of different testing to see who had been already contaminated (with antibody tests), for example.
He said 15% of the population has been contaminated, and many without even having any symptoms.
I've been following him for the last months, but most of the stuff is in German, not in English, hard to share.
What he basically says is:
1- it's pretty HARD to get infected from touching contaminated surfaces. He did his best to find LIVE viruses on door knobs of the most infected houses, but could not cultivate the virus live again. He only found dead viruses on all surfaces.
He analyzed door knobs, cat furs, mobile phones, computers, tables, clothes etc on and on again. No success.
2- he compares SarsCov2 to any corona viruses before. SarsCov1 was much more dangerous.
3- there's not such a thing as herd immunity, but this infection is not a monster infection like everyone is thinking (IFR he found in this super infected area was only 0.37%).
In the future it will be probably less, around the 0.2% he said in an interview, the more numbers he gets the case fatality rate goes down due to symptomless people.
4- the infection spreads easily in big events (such as carnival, discos, etc where people pack up in closed places, sing, dance, kiss, hug..).
He has a theory that only when a lot of infected people breathe in the same air in a closed environment, then you get a super spread.
The virus becomes more virulent (your get serious symptoms) the more the load of viral infection.
That's his thoughts after seeing thousands of cases.
5- He said that the more people in a household, the less they get infected. If you live on a household with 2 people, the chances the other person gets the Covid19 are higher than if you live in a household of 4 people.
Even being locked down with an infected person won't necessarily transmit the virus. Transmission of infection is rather low, he said.
You need more infected people and a higher load of viruses in the air to get the disease, he thinks.
6- there won't be a successful vaccine, he doesn't believe it. There were 6 corona viruses previously known, and not a single successful vaccine.
He's an HIV researcher, there's no vaccine for AIDS either.
There isn't total natural immunization from infection with corona viruses either.
But the virus get less and less virulent with the time, and the next waves of infection, if they happen, will be less severe, he says.
There is partial immunity from previous corona viruses infections in the population, and that is maybe another reason some people get less symptoms too (or no symptoms at all).
The guy is a wealth of knowledge.
He doesn't talk about governmental measures, but we can feel, in between the lines, that he thinks it's an exaggeration to still lock people now.
He said Germany did NOT test massively as other countries are suggesting, but he thinks they should have done that.