XFG, called Stratus by some, and NB.1.8.1, known as Nimbus, are now the most common variants being passed around in the UK, according to officials. Experts say these do not appear to pose any bigger threat than previous types of Covid or make people feel more ill. Have you got a razor blade sore throat? When the changes become significantly different, the new virus types are known as variants. For a sore throat, drinking plenty of fluids and having a teaspoon of honey may help, the NHS says.