London CNN  — 

London will return to a strict lockdown this week, after coronavirus cases soared in the British capital, UK Health Secretary Matt Hancock said Monday.

Hancock said London will be moved from England’s Tier 2 “high alert” local restrictions to the “very high” Tier 3 on Wednesday morning at 12:00 a.m., along with nearby areas in south and west Essex, and south Hertfordshire.

Under the highest restriction level, all hospitality venues including pubs, cafes and restaurants will close except for takeout and delivery.

People should avoid traveling outside their area and reduce the number of journeys they make wherever possible.

“Over the last three weeks we’ve seen very sharp exponential rises in the virus across London, Kent, parts of Essex and Hertfordshire,” said the health secretary.

In response to surging cases in London, the UK government is taking drastic action to contain the spread of the virus.

Residents in London are already unable to meet people from other households indoors, and will now not be able to meet in private gardens or at most outdoor venues. They may meet up to six people outside at parks, public gardens or sports facilities. Retailers will be able to stay open.

“We do not know the extent to which this is because of the new variant, but no matter its cause, we have to take swift and decisive action, which unfortunately, is absolutely essential to control this deadly disease while the vaccines roll out,” Hancock said Monday.

He said that in some areas, the doubling time for cases is now around every seven days, and that rates were rising not just among schoolchildren, “but in all age groups including the over 60s.”

Hospitals in London, Essex and Kent are already under pressure and could quickly be “overwhelmed” without action, he added.

Hancock said taking early actions that are “not necessarily easy, but are effective” was vital to prevent longer lasting damage, adding that community testing would also be extended.

“I know the steps are hard, but we must not waver as we enter the final stretch, so that when we look back on this time of crisis, we can all say that we played our part,” he added.

London joins regions including much of northern and central England, Kent in the southeast, and Bristol in the southwest in Tier 3.

However, people living in the UK will be allowed to form a “Christmas bubble” of up to three households between December 23 and 27. Households can only be in one bubble and may not switch.

Mayor of London Sadiq Khan said the decision was “incredibly disappointing for businesses, who have suffered so much already,” but said it was “clear that the virus is accelerating” and lives were at risk.

“It would be such a tragedy to lose even more people to this disease when the vaccine is now being rolled out across our city,” he said.

“We know from bitter experience that when cases start to rise quickly, it’s much better to act early, rather than too late. This is how we can avoid even tougher restrictions, for longer, further down the road.”

Hancock also said that a new variant of Covid-19 had been identified in the southeast of England.

The UK’s Chief Medical Officer, Chris Whitty, said Monday it was unclear whether the new variant had contributed to the surge in cases. Experts in the genetics of viruses said it not unexpected that mutation would arise and noted many had already been seen and had not significantly affected the spread or effects of the virus on people.

“I must stress at this point that there is currently nothing to suggest that this variant is more likely to cause serious disease, and the latest clinical advice is that it’s highly unlikely that this mutation would fail to respond to a vaccine,” Hancock said Monday.

Whitty, speaking later at a joint news conference, also stressed that there was no evidence that the new variant was more dangerous than the previous one. He also said that coronavirus tests had proven effective against the variant.

The British health secretary said similar variants had been identified in other countries in recent months, and that the UK had notified the World Health Organization about the new variant as expert analysis continues.

“It shows we’ve got to be vigilant and follow the rules, and everyone needs to take personal responsibility not to spread this virus,” Hancock said.

Multiple experts told the Science Media Centre that the new variant’s existence was unsurprising and unlikely to derail efforts to fight the pandemic.

“The emergence of different coronavirus strains…is neither cause for panic nor unexpected,” Dr Zania Stamataki, a viral immunologist at the University of Birmingham said Monday.

“Mutations will accumulate and lead to new virus variants, pushed by our own immune system to change or perish.”

“This virus doesn’t mutate as fast as influenza and, although we need to keep it under surveillance, it will not be a major undertaking to update the new vaccines when necessary in the future.

“Just because there has been a small change in the virus’ genetic makeup this does not mean it is any more virulent, nor that vaccines won’t be effective,” said Tom Solomon, professor of neurology at the University of Liverpool.

“Our experience from previous similar viruses suggests that the vaccines will be effective despite small genetic changes.”

This developing story has been updated with additional reporting.