The variant first identified in India currently accounts for more than 90 percent of Britain’s new COVID-19 cases.
Health authorities in Britain have said the new Delta coronavirus variant is 60 percent more transmissible in households than the previous dominant Alpha variant that forced the United Kingdom to lock down in January.
The Delta variant, which first emerged in India, has caused a rise in cases in Britain, prompting questions about whether physical distancing restrictions will be lifted as planned from June 21.
New research on Friday from Public Health England “suggests that the Delta variant is associated with an approximately 60 percent increased risk of household transmission” compared with the Alpha variant first identified in southeast England.
So far there have been 42,323 identified cases of the Delta variant in the UK, according to Public Health England’s data, up from 29,892 on June 2. The variant currently accounts for more than 90 percent of new COVID-19 cases.
The Alpha variant caused a surge of COVID-19 cases in January before a mass vaccine campaign, leading to a three-month lockdown as hospitals were stretched to near-capacity.
The government has since ramped up its vaccine drive, and has now administered nearly 41 million first doses and nearly 29 million second doses to adults over 25.
This means 43 percent of the total population are fully vaccinated and 18 percent are half vaccinated.
But cases are rising again, with new daily infections hitting 7,393 on Thursday, a level not seen since February. More than 90 percent of new cases were of the Delta variant, the government said.
However, the number of patients in hospital remains low, at just more than 1,000 on Thursday, and Health Secretary Matt Hancock has said most in-patients are people who are unvaccinated.
The government said this suggested the vaccination programme is mitigating the effect of the Delta variant, urging the public to get both jabs.
Jenny Harries, chief executive of the UK Health Security Agency, said that “two doses provide significantly more protection” against the Delta variant than one.
The UK has reported 127,867 deaths from the virus, the highest toll in Europe.
Under the government road map, England plans to drop rules on numbers at social gatherings and allow large weddings and the reopening of nightclubs from June 21.
But officials have stressed that they are open to changing this date if the virus situation changes as many businesses push for full reopening.
British Prime Minister Boris Johnson is due to announce on Monday whether the planned lifting of restrictions, which would see an end to limits on social contact, can go ahead on time.
“We have to be really careful. We had a very big opening on the 17th of May where people could meet friends indoors, in a restaurant, in a pub, and socialise indoors as well,” Nadhim Zahawi, COVID-19 vaccines minister, told Times Radio.
“And I think it’s important that we look at the data very carefully over this weekend and then share it with the nation.”