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.

Covid-19 has many variants, each presenting with different symptoms. Variant NB. 1.8.1 is being called razor blade throat due to symptoms it causes.