U.K. authorities are scrambling to contain a new mutated variant of the coronavirus that appears to be spreading rapidly. As yet, scientists don’t know much about the new strain, but the fact that it appears to increase in prevalence rapidly even during lockdown is causing serious concern among the British government.
Prime Minister Boris Johnson ordered new tier 4 restrictions for large swaths of the country on Saturday, effectively canceling Christmas get-togethers for millions — just days after he said such restrictions would be “inhuman.” That was followed on Sunday by a slew of travel bans on people coming from the U.K. by countries across Europe and beyond.
‘Mutant strain’ sounds scary. Is it?
Not in itself. The viral genetic material undergoes random changes all the time, though mutations are relatively sluggish in the coronavirus that causes COVID-19 (known scientifically as SARS-CoV-2). Many of these changes make little or no difference to the way the virus behaves. Others may make it more or less infectious or more or less deadly. But the two properties do not necessarily go together.
Is the new variant the first to emerge?
No and it certainly won’t be the last. One example is the so-called D614G variant with a mutation to part of the virus’s spike protein, which it uses to break into human cells. After appearing in January, by the summer it was found in almost all samples of the coronavirus worldwide. That appears to be because it is better at infecting cells and replicates in greater numbers.
Where is the new strain spreading?
Last Monday, the U.K.’s Health Secretary Matt Hancock announced in parliament that the new variant was spreading in the South East of England and at least 60 local authorities had identified cases caused by it. Maria Van Kerkhove from the WHO told the BBC’s Andrew Marr program that the new variant had been detected in Denmark and the Netherlands, as well as a case in Australia. Other cases have been found in Belgium and Italy, according to the European Centre for Disease Prevention and Control.
Is it more infectious?
After initial caution last week, scientists are becoming more convinced that the VUI-202012/01 variant of coronavirus is more transmissible. Notes from a meeting of the U.K.’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) on December 18 state that the group “has moderate confidence that VUI-202012/01 demonstrates a substantial increase in transmissibility compared to other variants.”
That might seem obvious given how quickly the strain appears to be spreading, but it can be hard to exclude other explanations such as a super-spreader event giving the variant a boost — particularly since scientists don’t know what might be making the viral strain more infectious. “Whilst previous variants have successfully emerged in periods of low prevalence without clear evidence of having a selective advantage, the emergence and subsequent dominance of VUI-202012/01 in a period of relatively high prevalence suggests VUI-202012/01 does have a selective advantage over other variants,” the scientists wrote.
Germany’s top virologist Christian Drosten on Monday morning noted that reports of the strain’s increased transmissibility had yet to be proven, adding that so far, he wasn’t “very worried.” He also said that the strain had “two possibly strengthening and one presumably weakening” mutation, as well as further “unclear” mutations.
How much faster is it spreading?
The new strain “has demonstrated exponential growth during a period when national lockdown measures were in place,” the NERVTAG notes state. The scientists estimate that the growth rate of the virus is 71 percent higher than other variants of the virus. That is boosting the R-value by between 0.39 and 0.93. That is very likely to push the R-value over 1, meaning that the epidemic grows rather than shrinks. One note of caution though: The mutant strain of the virus is hard to DNA sequence so this may be an underestimate.
It it more deadly?
“There is currently nothing to suggest that this variant is more likely to cause serious disease and the latest clinical advice is that it is highly unlikely that this mutation would fail to respond to a vaccine,” Hancock told MPs last week.
The NERVTAG scientists say there is currently insufficient data to say what the mechanism of increased transmissibility is or whether the variant is more deadly. So far, four deaths in around 1,000 cases have been identified. As yet, there is also not enough data to draw definitive conclusions on the age profile of people infected and whether the mutated virus is recognized by the immune system of someone who has already had the virus — or indeed has been vaccinated. Worryingly though they state: “Four probable reinfections have been identified amongst 915 subjects with this variant.”
How are other countries reacting?
Several countries in Europe and around the world have introduced temporary bans on travel from the U.K. in an attempt to avoid importing the new viral strain including France, Germany and Belgium. More detail here.