In recent days, the world has watched with curiosity and growing alarm as scientists in Britain have described a newly identified variant of the coronavirus that appears to be more contagious than, and genetically distinct from, more established variants. Initial studies of the new variant prompted Prime Minister Boris Johnson to tighten restrictions over Christmas, and spurred officials in countries around the world to ban travel from Britain.
Here’s what scientists have learned about it so far.
Is the British variant some kind of new supervirus?
No. It’s just one variation among many that have arisen as the coronavirus has spread around the world. Mutations arise as a virus replicates, and this variant — known as B.1.1.7 — has acquired its own distinctive set of them.
Is it more contagious than other viruses?
It appears so. In preliminary work, researchers in Britain have found that the virus is spreading quickly in parts of southern England, displacing a crowded field of other variants that have been circulating for months.
However, a virus lineage becoming more common is not proof that it spreads faster than others. It could grow more widespread simply through luck. For instance, a variant might start out in the middle of a crowded city, where transmission is easy, allowing it to make more copies of itself.
Still, the epidemiological evidence gathered so far from England does seem to suggest that this variant is very good at spreading. In places where it has become more common, the overall number of coronavirus cases is spiking. Neil Ferguson, an epidemiologist at Imperial College London, estimates that the variant has an increased transmission rate of 50 to 70 percent compared with other variants in Britain.
Does it cause more severe disease?
There is no strong evidence that it does, at least not yet. But there is reason to take the possibility seriously. In South Africa, another lineage of the coronavirus has gained one particular mutation that is also found in B.1.1.7. This variant is spreading quickly through coastal areas of South Africa. And in preliminary studies, doctors there have found that people infected with this variant carry a heightened viral load. In many viral diseases, this is associated with more severe symptoms.
Is the variant already circulating in the U.S.?
Not yet, as far as anyone knows. But that does not mean it hasn’t already reached the United States. British scientists have established a much stronger system to monitor coronaviruses for new mutations. It’s conceivable that someone traveling from Britain has brought it with them.
Will the variant render the new vaccines ineffective?
No. Most experts doubt that it will have any great impact on vaccines, although it’s not yet possible to rule out any effect.
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