A new COVID-19 variant is spreading across the United States, but experts warn that this variant has a new painful symptom.

A new COVID variant called "Nimbus" is spreading. Here's what you need to know about the incubation period, symptoms (including "razor blade throat") and when to take a test.

COVID-19 is essentially a respiratory infection that infects the body through the nose, mouth, and throat, which are part of the upper respiratory tract. In the early days of infection, the virus multiplies in the lining of the throat.