The UK is in the early stages of a third wave of Covid-19, a scientist advising the UK government said, media reports said on Monday.
The B1617 variant had fuelled "exponential growth" and is responsible for at least three-quarters of cases in the UK, Ravi Gupta, a professor at the University of Cambridge, was quoted as saying by the BBC.
"Of course the number of cases is relatively low at the moment — all waves start with low numbers of cases that grumble in the background and then become explosive, so the key here is that what we are seeing here is the signs of an early wave," Gupta told BBC Radio 4's Today programme.
However, he said the number of people who have been vaccinated in the UK meant this wave would probably take longer to emerge than the previous ones.
"There may be a false sense of security for some time, and that's our concern," he noted, suggesting that ending Covid restrictions in the UK on June 21 should be postponed.
It should be delayed "by a few weeks while we gather more intelligence", said Gupta, a member of the UK government's New and Emerging Respiratory Virus Threats Advisory Group (Nervtag).
The concern was echoed by other experts who said that the B1617 variant could "pick up speed and become a big problem" in the UK as the country further eases lockdown measures.
The UK's fight against coronavirus could turn bad "very, very quickly" unless the government acts cautiously on easing lockdown further, Xinhua news agency quoted Tim Gowers from the University of Cambridge telling the Guardian on Saturday.
Anthony Harnden, the deputy chair of the UK's Joint Committee on Vaccination and Immunisation (JCVI), also warned that the B1617 variant is "clearly more transmissible".
"We need to be reassured that we're in a very different position now in that we've got a highly vaccinated population and we just need to continue moving at speed," he told the BBC on Saturday.
"We do know that with this particular variant, you do need two doses to offer complete protection, and so we're very, very keen to make sure that all those, particularly higher risk groups, over 50 years of age and those with underlying illness, receive their second vaccination as soon as feasible," Harnden said.
The final stage of the government's roadmap for lifting lockdown, which would remove all limits on how many people you can meet – either indoors or outdoors, is due no earlier than June 21.
On Sunday, the UK reported more than 3,000 new Covid infections for a fifth day in a row. Prior to this, the UK had not surpassed that number since April 12, the BBC report said.
