The Omicron variant has become the dominant strain of Covid in England, official statistics suggest.
Analysis of samples by the UK Health Security Agency (UKHSA) suggests the latest Covid-19 strain has overtaken Delta as the most common strain found in all regions of the country.
The news comes after early studies suggested Omicron carried a lower risk of hospitalisation despite being more transmissible.
But a full evaluation of the latest coronavirus strain is yet to take place, amid a record-breaking spike in cases.
Thus far, the Prime Minister Boris Johnson has not brought in any new Covid restrictions for England.
The devolved administrations in Scotland, Wales and Northern Ireland have all announced that more stringent curbs on public life will be implemented after Christmas in a bid to control the virus’ spread.
What has UKHSA reported?
UKHSA’s findings indicate that the Omicron variant has become the driver of the current spike in infections in England.
Some 90.2% of a sample of new Covid cases in London collected between December 19 and 20 were found to have characteristics consistent with Omicron.
The North East of England, which had been the last remaining region where Omicron wasn’t dominant, reported that 56.8% of a sample of its detectable cases had been caused by the latest variant over the same time period.
For Eastern England the equivalent figure was 80%, followed by the North West at 77.6%, the South East at 76.4%, and the East Midlands with 74.4%.
The South West is on 73.2%, the West Midlands 72.1%, and the Yorkshire and Humber region 71%.
Overall, Omicron is believed to be behind 76% of Covid cases in England.
How did researchers work out these figures?
The UKHSA has been able to track Omicron thanks to how different it is to previous variants of Covid-19.
Most samples of Omicron that have been sequenced in a laboratory have been found to have a small but identifiable difference to previous strains, like Delta.
This difference – in the S gene – shows up in some laboratory PCR tests and can be used as a way of estimating the spread of Omicron.
All the UKHSA figures are based on samples tested at four of the UK’s Lighthouse laboratories.
These are at the Alderley Park campus in Cheshire, Glasgow, Milton Keynes and Newcastle.
It means there are likely to be some areas of England where the prevalence of Omicron is currently being underreported.