For the first time we have true randomized testing — and it shows that Austria was officially picking up about a quarter of the real number of infections in the population. So when Austria was officially saying 7,000 were infected, the true number was 28,500. Finally, this puts a solid limit on the chance that asymptomatic rate of infection was high. There is no iceberg.
About 75% of cases were mild or truly asymptomatic (and thus not getting officially tested), but it was still only a small slice of the population — just one third of one percent.
The study some are quoting from an area of Chicago has a headline suggesting 30% of the population already had the virus, but closer reading showed it was less than 1%. The second half of the first sentence of the article reveals that the rate was only about three times those who were known to have the virus (which is much less than 1% of the population). Turns out the sample was at a clinic for people with symptoms. Talk about grasping at straws.
Herd immunity requires about 70% of the population to be immune. In Australia, with about 6,000 known cases and thus probably about 18,000 unknown infections, we are probably at about 25,000 infections. With 0.1 percent of the population infected, Australia is still about 17 million short of the 17 million required for herd immunity.