Cases of the Delta variant of coronavirus first identified in India are estimated to be doubling every four and a half days in parts of England, new data suggests.
Public Health England (PHE) said on Friday that 42,323 cases of the Delta variant that originated in India have been confirmed in the UK, up by 29,892 from last week.
Growth rates for Delta cases are high across all parts of the country, it added, with regional estimates for doubling time ranging from 4.5 days to 11.5 days.
The growth rate was shortest in the West Midlands and Yorkshire and the Humber and longest in the East of England, PHE said.
In England 39,061 cases of the Delta variant of coronavirus have been confirmed, along with 3,035 in Scotland, 184 in Wales and 43 in Northern Ireland.
PHE also said that more than 90% of new Covid-19 cases are now the Delta variant, with new research suggesting it is associated with an approximately 60% increased risk of household transmission compared with the Alpha or Kent strain.
But it added that the increase in confirmed cases from 12,341 last week has been driven partly by a reduction in test turnaround times and a faster process for identifying cases of the variant.
Lib Dem MP Layla Moran, chairwoman of the All-Party Parliamentary Group (APPG) on Coronavirus, said: “These figures should set alarm bells ringing in Government as we approach the June 21.
“The Government must immediately explain to the public whether this exponential growth suggests the country is in line for a severe third wave, and if so what it is doing to prevent this.
“As well as hospitalisations and deaths, ministers need to consider the debilitating impact of long Covid which is already affecting an estimated one million people.
“Simply letting this highly contagious strain of the virus rip through unvaccinated younger people risks leaving more with long Covid and creating a ticking time bomb for our NHS.”
As of June 7, there have been 42 deaths in England of people who were confirmed as having the Delta variant of Covid-19 and who died within 28 days of a positive test, according to PHE.
Of these, 23 were unvaccinated, seven were more than 21 days after their first dose of vaccine and 12 were more than 14 days after their second dose.
The figures also showed that two thirds of the 1,234 people who attended A&E in England between February 1 and June 7 and who were confirmed as having the Delta variant of coronavirus were unvaccinated.
A total of 220 (18%) were more than 21 days after their first dose of vaccine, and 83 (7%) were more than 14 days after their second dose, PHE added.
Of the 383 cases where attendance at A&E resulted in an overnight admission, 251 (66%) were unvaccinated, 66 (17%) were more than 21 days after their first dose of vaccine and 42 (11%) were more than 14 days after their second.
Dr Jenny Harries, chief executive of the UK Health Security Agency, said: “With numbers of Delta variant cases on the rise across the country, vaccination is our best defence.
“If you are eligible, we urge you to come forward and be vaccinated.
“Remember that two doses provide significantly more protection than a single dose.
“However, while vaccination reduces the risk of severe disease, it does not eliminate it.
“With data showing that Delta is significantly more transmissible than Alpha, it is just as important as ever to follow public health advice, which has not changed.
“Get vaccinated, work from home where you can and remember ‘hands, face, space, fresh air’ at all times.
“These measures work, and they save lives.”