A new commercially available test called T-Detect has received emergency use authorization from the FDA. The manufacturer says it has the power to tell most patients whether or not they've been infected with coronavirus in the past.

We first met Rick St. John at Stanford, in a special study of what's come to be known as long haul COVID-19. While his symptoms have persisted for months, he says in the beginning they were mild enough that he almost went undiagnosed.

source: https://abc7ny.com/10411997