For COVID-19 researchers, the new year brings a strong sense of déjà vu. As in early 2020, the world is anxiously watching a virus spread in one country and trying to parse the risk for everyone else.
Complex scenario
This time it is not a completely new threat, but a rapidly spreading variant of SARS-CoV-2. In southeastern England, where the B.1.1.7 variant first caught scientists’ attention last month, it has quickly replaced other variants, and it may be the harbinger of a new, particularly perilous phase of the pandemic.
“One concern is that B.1.1.7 will now become the dominant global variant with its higher transmission and it will drive another very, very bad wave,” says Jeremy Farrar, an infectious disease expert who heads the Wellcome Trust.
Whereas the pandemic’s trajectory in 2020 was fairly predictable, “I think we’re going into an unpredictable phase now,” as a result of the virus’ evolution, Farrar says.
The concern has led some countries to speed up vaccine authorizations or discuss dosing regimens that may protect more people rapidly.
But as the new variant surfaces in multiple countries, many scientists are calling for governments to strengthen existing control measures as well. U.K. Prime Minister Boris Johnson announced tough new restrictions on 4 January, including closing schools and asking people not to leave their homes unless strictly necessary.
But other countries have hesitated. “I do feel like we are in another situation right now where a lot of Europe is kind of sitting and looking,” says virologist Emma Hodcroft of the University of Basel. “I really hope that this time we can recognize that this is our early alarm bell, and this is our chance to get ahead of this variant.”
In announcing the U.K. restrictions, Johnson said the new variant is between 50% and 70% more transmissible. But researchers have been careful to point out uncertainties.
Cases have soared in the United Kingdom over the past month, but the rise occurred while different parts of the country had different levels of restrictions and amid changes in people’s behavior and regional infection rates in the run-up to Christmas—“a complex scenario” that makes it hard to pinpoint the effect of the new variant, says evolutionary biologist Oliver Pybus of the University of Oxford.
Yet evidence has rapidly increased that B.1.1.7’s many mutations, including eight in the crucial spike protein, do enhance spread.
“We’re relying on multiple streams of imperfect evidence, but pretty much all that evidence is pointing in the same direction now,” says Adam Kucharski, a modeler at the London School of Hygiene & Tropical Medicine.
For instance, an analysis by Public Health England showed about 15% of the contacts of people infected with B.1.1.7 in England went on to test positive themselves, compared with 10% of contacts of those infected with other variants.
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Source: Science
This is old news concerning the Alpha variant?