What does it mean if a person’s rapid antigen test result comes back positive after five days of isolation due to COVID-19? According to the experts, that person is most likely still carrying a viral load high enough to infect others.

“Anytime you’re positive by one of these rapid at-home covid tests, it means that you’ve still got a really high level of the viral protein, and most experts are interpreting that as a high level of virus present in your nasal passage,” said Matthew Binnic...