What scientists know about the mutant coronavirus strand spreading in the U.K.

LONDON — Several European countries have banned flights from the U.K. over fears about new coronavirus variant that has forced millions of people in Britain to cancel their Christmas plans.

Germany, the Netherlands, Belgium, Austria and Italy all announced restrictions on U.K. travel. Others will likely follow suit as scientists warned the new strain spread more quickly than its predecessor.

With U.K. infection levels rising rapidly, Britain’s Prime Minister Boris Johnson told a Saturday news conference that London and the U.K.’s southeast would be put under the strictest lockdown rules, known as “Tier 4.”

As a result, nonessential shops, gyms, cinemas, hairdressers and bowling alleys will be forced to close for two weeks, while people will be restricted to meeting one other person from another household in an outdoor public space.

A “bubble” policy — allowing up to three households to meet over the holiday period in parts of the country that are not under Tier 4 restrictions — will be severely curtailed and will only apply on Christmas Day, Johnson said.

U.K. health officials first identified the new variant, which British scientists have called “VUI – 202012/01,” in mid-September, Maria Van Kerkhove, the Covid-19 technical lead for the World Health Organization, told the BBC Sunday.

It is “very common” for viruses to mutate, Simon Clarke, an associate professor in cellular microbiology at the U.K.’s University of Reading, told NBC News.

“When they cause an infection, they get inside our cells and take over the cell to make more copies of themselves to reproduce, and every time they do that a new set of genetic material was made for each new virus,” he said, adding that the new strain is “certainly fitter” than its predecessor.

Professor Chris Whitty, the chief medical officer for England, warned in a statement Saturday that it is considered to be spreading more quickly.

But he said there was no evidence so far to suggest that the new strain is more potent in terms of severe illness or fatality.

“Our working assumption from all the scientists is that the vaccine response should be adequate for this virus,” Sir Patrick Vallance, the U.K. government’s chief scientific adviser, told a news briefing Saturday.

But Ravindra Gupta, a professor of clinical microbiology at the University of Cambridge, said he was concerned that the virus is kind of on a pathway to becoming resistant to vaccines.

“Whilst it may not be actually resistant, it may not take so many changes after this for it to get there,” he told NBC News.

However, Clarke said different versions of flu vaccines are required every year, and he did not see why it could not be the same for the coronavirus.

The new variant has so far been identified in Denmark, the Netherlands and Australia, Van Kerkhove said.

“The longer this virus spreads, the more opportunities it has to change, so we really need to do everything we can right now to prevent spread. Minimizing that spread will reduce the chances of it changing,” she said.

More sequencing that can be done will be helpful to determine if this variant is circulating elsewhere, she added.

Gupta said the new strain should be cause for concern in the U.S. and other countries around the world. Warning that the virus could mutate again, he said, “People need to step up their surveillance.”

In the U.K., the tough new lockdown restrictions were a “necessary measure” to control the virus, Dr. Julian Tang, a clinical virologist at the University of Leicester, said in a statement. But he warned that even a few hours on Christmas Day could still result in infection.

Officials are therefore urging people in lower tiers across England to still maintain social distancing as much as possible.

Dec. 20, 202002:47

While scientists have praised Johnson for increasing restrictions, his political rivals have accused him of causing “heartbreak” for millions of families because of the last-minute restrictions.

Sir Keir Starmer, leader of the opposition Labour Party, called on Johnson to apologize to the public for the way the lockdown had been handled.

“At the heart of the problem here is a prime minister who simply doesn’t want to be unpopular and therefore won’t take the tough decisions that are necessary, until he is forced into them at the eleventh hour,” he told an online news conference.