Patients and doctors say the latest COVID-19 variant spreading in the U.S. in some cases causes a sore throat so painful it has earned the nickname “razor blade throat.” The nimbus variant, which is officially known as NB.

COVID-19 appears to be on the rise in some parts of California as a new, highly contagious subvariant — featuring 'razor blade throat' symptoms overseas — is becoming increasingly dominant.

A newer COVID-19 variant may be causing a severe sore throat in those who contract the infections. Here's what to know about "razor blade throat."