The variant of Covid-19 first identified in India is now the dominant strain of the virus in England, data shows.
Figures published by Public Health England show that the Delta variant accounts for over nine in ten cases that are sequenced for their genetic lineage.
The data comes as England faces a four-week delay to the final stage of lifting lockdown restrictions, following concern among the Prime Minister and his scientific advisers that Delta could lead to a significant rise in infections and hospital admissions if rules are further eased.
Where is the Indian variant in the UK?
Areas where Delta has the strongest foothold have already seen increases in both, as the evidence continues to suggest that the strain can spread more easily than the previously dominant Alpha variant, which emerged in Kent at the end of last year.
However, ministers have stressed that the Covid-19 vaccine is very effective against the Delta variant and are continuing to urge people to get their jab.
Data compiled by the Wellcome Sanger Institute shows prevalence of the Indian variant continues to be high in the North West of England in Bolton and Blackburn with Darwen – two local authorities that have seen extra vaccinations deployed in an attempt to protect residents against Delta’s tightening grip on their local areas.
Laboratory results in the two weeks up to June 2 suggested that practically 100 per cent of cases from the community in these areas were identified as Delta – up from closer to 20 per cent at the end of April.
Yet data shows the variant has now clearly spread beyond these hot spots to most of England now, with local authorities in all parts of the country – from London to the South West to the Midlands – seeing B.1.617.2 dominating local sequencing data in the two weeks to May 22.
Public health officials are continuing to monitor the prevalence and impact of Delta, ahead of the next opportunity for restrictions to be eased in England on July 19.