Covid-19 cases that return after antiviral treatment puzzle doctors
The pink line on Erin Blakeney’s first positive Covid-19 test was so light that she almost didn’t believe it, But there was no denying the fever and sore throat that developed overnight, just a few days after she and her husband attended a large memorial service in late March. The couple wore KN95 masks, but many others in attendance had not, even as the service stretched past 90 minutes.
