That's because the variant — NB.1.8.1. or “Nimbus” — may cause painful sore throats. The symptom has been identified by doctors in the United Kingdom, India and elsewhere, according to media outlets in those countries. Other COVID-19 symptoms of any variant include fever, chills, cough, shortness of breath or loss of taste or smell.

A new COVID strain has become increasingly more common in the U.S. in recent weeks and can cause a painful symptom that some are calling "razor blade throat." COVID variant, NB.1.8.1, nicknamed Nimbus,