Don't refer to Sweden ... (despite the fact I like this country and it's inhabitants very much)

+++ After two mishaps in central coronavirus studies, there is great uncertainty in Sweden. It is now completely unclear how many people had already contracted and could be immune.

The matter is as embarrassing as it is complicated, because Swedish experts apparently made two mutually independent but fundamental errors: a study in which corona antibodies were searched twice in 100 blood donations and found in eleven percent of the samples, was withdrawn from the Karolinska Institute.

Reason: "It cannot be ruled out that the samples also included those from known corona people whose plasma was intended to help seriously ill patients. This means that the assumption that a correction factor including 20 to 30 percent of all Swedes has actually been infected and could therefore be immune is no longer tenable."

And state epidemiologist Anders Tegnell also had to back down. According to a study, the health authority suspected that there were 999 undetected cases for every corona case in Sweden. With around 6,400 sufferers in Stockholm alone, however, this would have meant more than six million infected people, while the city is home to just under a million people.

Tegnell tried to explain the obvious mistake:
"You used an incorrect variable and thus increased another variable to meet the specified guideline value of two and a half percent of infection. This increased the value between confirmed and undetected cases enormously. We should have noticed that, but it does not change anything other facts like when the infection rate peaked. " +++

ref: transscript from a German TV (ARD) podcast