Public health England says the delta variant of Covid is 60% more infectious than Alpha - the Kent variant - and vaccines are less effective at beating it.
More than 90% of new Covid-19 cases are now the Delta variant, which continues to show a significantly higher rate of growth compared to the Alpha (or Kent) variant, Public Health England said.
New research suggests the Delta variant is associated with an approximately 60% increased risk of household transmission compared with the Alpha variant.
Growth rates for Delta cases are high across all parts of the country, with regional estimates for doubling time ranging from 4.5 days to 11.5 days.
A total of 42,323 cases of the Delta variant of coronavirus that originated in India have now been confirmed in the UK, up by 29,892 from last week, Public Health England said.
In England, 39,061 cases of the Delta variant of coronavirus have now been confirmed, along with 3,035 in Scotland, 184 in Wales and 43 in Northern Ireland.
The increase in the overall UK total – from 12,341 last week to 42,323 this week – has been partly driven by a reduction in test turnaround times and a faster process for identifying cases of the variant, Public Health England said.
