What Is the New COVID-19 Strain That Shut Down London?

An empty St. Pancras train station in London on December 20. Photo: Getty Images

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On Saturday, Prime Minister Boris Johnson instituted the United Kingdom’s strictest coronavirus restrictions since the initial lockdown in March, banning holiday gatherings of more than one household and closing all nonessential stores in a zone which includes greater London and much of the southeast of England. The cause for caution is a new COVID-19 mutation active on the island, which has helped the rate of new infections almost double in the past two weeks.

“This virus spreads more easily,” the U.K.’s chief scientific adviser, Patrick Vallance, said on Saturday. “And therefore more measures are needed to keep it under control.”

Neighboring nations agree. Though the virus strain is not expected to be resistant to the vaccines rolled out earlier this month, France, Spain, Italy, and several other European nations have temporarily banned travel from the United Kingdom as scientists race to learn more about the mutation. Below is a primer for the public-health and political ramifications of the concerning development.

How is this COVID strain different?

The variation found in the U.K., known as “VUI – 202012/01” was first identified there in mid-September, according to the World Health Organization. Its mutations have occurred on the genetic material that controls the spike protein, which allows COVID and other similar viruses to penetrate host cells, causing infection.

According to the U.K.’s chief scientific adviser, Patrick Vallance, there are 23 changes in the virus’s genetic material, an unusually large number that appears to be helping it spread more quickly. British officials have now estimated that “VUI – 202012/01” is as much as 70 percent more transmissible — a number that is based on modeling, but not yet confirmed in lab experiments. Though there is no evidence to-date that the strain causes a more intense illness or leads to a higher fatality rate, faster transmission does mean more cases, which can lead to a higher hospitalization rate.

Are coronavirus variations common?

In general, viruses are prone to picking up small genetic changes as they move through a host population. “Viruses that encode their genome in RNA, such as SARS-CoV-2, HIV and influenza, tend to pick up mutations quickly as they are copied inside their hosts, because enzymes that copy RNA are prone to making errors,” Nature writer Ewen Callaway explains.

Scientists have been tracking minor changes in the COVID-19 genetic code since the beginning of the pandemic, and at least 1,000 variants have been detected so far. But the change to the spike protein found in southeast England represents one of the first coronavirus mutations that have made it more infectious.

As the Wall Street Journal notes, this isn’t the first time that COVID mutations have resulted in a more transmissible strain of the virus:

Scientists in July described a variant that over time displaced an older strain of coronavirus to become the dominant strain in the global pandemic. Experiments showed that variant, known as G614, replicated more quickly, but appeared to be just as susceptible to antibodies that target the earlier strain and wasn’t associated with more severe illness.

How will the vaccine rollout be impacted by the U.K. strain?

“Our working assumption from all the scientists is that the vaccine response should be adequate for this virus,” Vallance said in a briefing on Sunday. Thus, the strain that has shut down southeast England will not cut off the inoculation effort that began on December 8.

U.S. scientists at the Walter Reed Army Institute of Research are still studying the mutation, but Dr. Nelson Michael, director of the institute’s Center for Infectious Diseases Research, agreed that the current vaccines will probably be effective against the new variant. “It stands to reason that this mutation isn’t a threat, but you never know. We still have to be diligent and continue to look,” Michael told CNN.

However, microbiologists that spoke with NBC News shared concerns that the virus could eventually grow to become vaccine-resistant. “Whilst it may not be actually resistant, it may not take so many changes after this for it to get there,” said Ravindra Gupta, a professor of clinical microbiology at the University of Cambridge. Simon Clarke, an associate professor in cellular microbiology at the University of Reading, said the COVID vaccine could eventually become like the flu shot, requiring an updated version every year.

Which countries have banned travel from the United Kingdom?

On Sunday, the Netherlands and Belgium were the first nations to suspend air travel from the United Kingdom. They were soon joined by Austria, Germany, Ireland, Spain, Italy, and Israel, while the French ban also appears to apply to travel over the English Channel as well. On Monday, the European Union will meet to discuss a coordinated effort.

Before Boris Johnson announced the new restrictions on Saturday, the United States already blocked travel for most non-U.S. citizen who had recently been to the U.K., Ireland, Brazil, and 26 other European nations. According to a report from the Telegraph the day before Johnson’s announcement, President Trump was considering lifting that ban — though the lockdown may change the calculus on that decision.

Are new virus strains active anywhere outside Britain?

Scientists in South Africa have detected a strain that shares one of the mutations of the British coronavirus in up to 90 percent of samples that have been genetically sequenced since mid-November. Evidence suggests that the two variations have arisen separately, according to molecular epidemiologist Emma Hodcroft. Though the variant has not been connected to more severe cases, it is associated with higher viral loads in swab tests, meaning that it is also more transmissible.

South Africa, the hardest-hit nation on the continent, is currently experiencing a second wave driven in part by this more virulent strain and in part by behavior that has undermined public-health measures throughout the pandemic — including a recent party at a beach town on the Indian Ocean, where over 1,000 attendees have already tested positive for COVID-19. At a WHO meeting earlier this month, scientists reported that the new variant made up 80 to 90 percent of infections in South Africa.

This post has been updated.

What Is the New COVID-19 Strain That Shut Down London?