British Prime Minister Boris Johnson ordered a new national lockdown in England on Jan. 4 to try to slow a surge in coronavirus cases. (Video: Reuters)

LONDON — Prime Minister Boris Johnson on Monday ordered a third national lockdown for England amid a surging coronavirus outbreak driven by a U.K. variant that appears to be more contagious and may have greater implications for children.

In a televised address to the nation Monday evening, Johnson said the new variant was 50 to 70 percent more transmissible, spreading at a rate he called “frustrating and alarming.”

“With most of the country already under extreme measures, it’s clear that we need to do more together to bring this new variant under control while our vaccines are rolled out,” he said. “In England, we must, therefore, go into a national lockdown which is tough enough to contain this variant.”

Speaking on a visit to a hospital in London earlier in the day, Johnson said, “We have a new variant that is requiring extra-special vigilance.” The variant has spread to more than 30 countries.

The Monday announcement comes after a national lockdown in March and then a four-week one that began in November.

The government had been facing growing calls to impose further restrictions as coronavirus cases continue to skyrocket. On Monday, Britain recorded 58,784 new daily cases, the highest figure recorded here during the pandemic.

“Let me be candid with you: This virus is out of control,” London Mayor Sadiq Khan told LBC Radio earlier Monday. “We have more patients in hospital in London now with covid than anytime in March, April and May during the peak. Plus, we have the additional non-covid winter pressures.”

Britain has recorded more than 50,000 daily cases for seven days. The number of patients in London hospitals has more than doubled over the past two weeks. At least one London hospital has had to postpone urgent cancer surgeries this week because it is overwhelmed with covid patients.

Under the new lockdown, everyone in England will be asked to stay at home except in special circumstances. Schools and universities will close for in-class learning with immediate effect.

In his televised address, Johnson said: “I want to stress that the problem is not that schools are unsafe for children — children are still very unlikely to be severely affected by even the new variant of covid.

“The problem is that schools may nonetheless act as vectors for transmission, causing the virus to spread between households.”

The more contagious variant, which has spread to dozens of countries and has been detected in four U.S. states, may have had a disproportionate effect on people under 20 in Britain, according to a new report that has not gone through scientific peer-review.

When the study authors evaluated patients by age, they found a slightly higher proportion of variant vs. non-variant cases in people younger than 20. The researchers’ observations cannot explain why. The difference they detected may have been circumstantial.

The fresh lockdown comes as Britain began rolling out the Oxford-AstraZeneca vaccine. Early Monday morning, Brian Pinker, 82, became the first person in the world to get a shot of the vaccine outside of clinical trials. The former maintenance manager rolled up his sleeve at a hospital in Oxford, where the vaccine was developed. “The vaccine means everything to me. To my mind, it’s the only way of getting back to normal life,” Pinker said afterward.

The government hopes that the Oxford-AstraZeneca vaccine, which is cheaper to produce and easier to transport than other vaccines that are being administered, will be a “game changer.” Nursing home residents, health-care workers and those over 80 are at the front of the line. Britain recently shifted its vaccine strategy so that it could inject as many people as possible, as quickly as possible, by allowing for 12 weeks between the first and second dose instead of the usual 21 days.

But inoculating an entire nation will take months, and the growing number of cases and hospitalizations has sparked alarm in Britain.

As U.K. coronavirus cases hit record high, health-care workers are overwhelmed

Scotland’s semiautonomous government also announced a new lockdown Monday for at least the rest of the month. Nicola Sturgeon, the first minister of Scotland, told the Scottish Parliament that starting Tuesday, there would be “a legal requirement to stay at home except for essential purposes. This is similar to the lockdown of March last year.”

She also said that students would move to remote learning for the rest of the month.

Sturgeon said that the “overall level of community transmission is simply too high” to keep schools open and that there was still “significant uncertainty about the impact of the new variant on transmission amongst young people.”

In England, schools will move to remote learning Tuesday.

More than three-quarters of England was already at “Tier 4,” the highest level of restrictions.

Health Secretary Matt Hancock told the television program “Good Morning Britain” on Monday that Britain’s temporary “Nightingale hospitals,” built in weeks last year, were on “standby if needed.”

The National Health Service said in a statement that it was “working hard” to ready London’s flagship Nightingale hospital to treat patients “if necessary.” The London center will be used to rehabilitate people who are recovering from an emergency stay in a hospital and will not be used to treat patients who have covid-19, the statement said.

British media outlets have reported in recent days that the majority of the seven Nightingale hospitals had been dismantled or were not being used as cases began to climb in the country again — prompting many to question why.

ICU nurse Dave Carr told “Good Morning Britain” on Monday that the rise in infections was “breaking” exhausted NHS staff working in intensive care units in London that are full with patients, who are forced to share ventilators.

“The admissions keep coming in,” Carr said, adding that all available staff are already working at NHS hospitals and finding staff for the Nightingale facilities would be difficult. “It’s absolutely appalling planning,” he said of the government’s handling of the crisis.

Former health secretary Jeremy Hunt was among those on Monday urging the government to “close schools, borders, and ban all household mixing RIGHT AWAY.”

“To those arguing winter is always like this in the NHS: you are wrong,” he tweeted. “I faced four serious winter crises as Health Sec and the situation now is off-the-scale worse than any of those.”

Guarino reported from New York.

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