vscientist

jupp0r is correct; this is a real problem for a disease that is so contagious.

Lets say the covid-19 (real) prevalence is 0.1% in the US now. That means 10k infected people for every 10 Million people. If 10M take the test, 97.90 % sensitivity means, of the 10k (true) infected people, 210 will show up as negative. If these people go out and "mingle", there is potential for the infection to pick up again.