Cases of the Omicron sub-variant BA.2 have been in the UK for some time after the first example was found on December 6, 2021.
But numbers are growing both here and abroad, and the UK Health Security Agency named it a ‘variant under investigation’ on January 21.
In the latest analysis, up to January 15, one case was found in Derby. No other BA.2 cases were detected in the county.
Early analysis suggests it has a faster growth rate than the Omicron strain currently dominant in the UK, BA.1, but there is not enough evidence to say whether it causes more severe illness.
The Wellcome Sanger Institute analysed 38,000 positive Covid-19 tests taken in the week to January 15 to determine which variant they were.
It found one in 100 samples were now Stealth Omicron across England.