A new variant of the pandemic SARS-CoV-2 coronavirus is spreading in Britain and prompting high levels of concern, especially among the country’s European neighbours, some of which have cut transport links.
The variant, referred to by some experts as the B.1.1.7 lineage, is not the first new variant of the pandemic virus to emerge, but is said to be up to 70 per cent more transmissible than the previously dominant strain in the United Kingdom, based on modelling.
Virus mutations seen so far
In April, researchers in Sweden found a virus with two genetic changes that seemed to make it roughly two times more infectious, said Dr. Ravi Gupta, who studies viruses at the University of Cambridge in England. About 6,000 cases worldwide have been reported, mostly in Denmark and England.
Several variations of that strain now have turned up. Some were reported in people who got them from mink farms in Denmark. A new South African strain has the two changes seen before, plus some others.
Britain’s chief scientific adviser Patrick Vallance said on Saturday he thought the new variant might have started in the U.K.
The cause for concern
The new variant has rapidly become the dominant one in cases of COVID-19 in parts of southern England, and has been linked to an increase in hospitalization rates, especially in London and in the adjacent county of Kent.
While it was first seen in Britain in September, by the week of Dec. 9 in London, 62 per cent of COVID-19 cases were as a result of the new variant. That compared to 28 per cent of cases three weeks earlier.
The governments of Australia, Italy and the Netherlands say they detected cases of the new strain. It was identified in the Netherlands in early December.
LISTEN l A U.K professor of microbiology talks about the new strain detected:
Daybreak Montreal9:26A new strain of COVID-19 is spreading in the UK
A few cases of COVID-19 with the new variant have also been reported to the ECDC, Europe’s disease monitoring agency, by Iceland and Denmark. Media reports in Belgium say cases have also been detected there.
“It is right to take it seriously,” said Peter Openshaw, a professor of experimental medicine at Imperial College London.
Shaun Fitzgerald, a visiting professor at the University of Cambridge, said the situation was “extremely concerning.”
The concerns, explained
The main worry is that the variant is significantly more transmissible than the original. It has 23 mutations in its genetic code — a relatively high number of changes — and some of these are affecting its ability to spread.
Some of the mutations are on the spiky protein that the virus uses to attach to and infect cells. That spike is what current vaccines target.
“I’m worried about this, for sure,” but it’s too soon to know how important it ultimately will prove to be, said Gupta.
Scientists estimate it is about 40 to 70 per cent more transmissible. The U.K. government said on Saturday it could increase the reproduction R rate by 0.4.
This means it is spreading faster in Britain, making the pandemic there yet harder to control and increasing the risk it will also spread swiftly in other countries.
“The new B.1.1.7 … still appears to have all the human lethality that the original had, but with an increased ability to transmit,” said Martin Hibberd, a professor of emerging infectious disease at the London School of Hygiene & Tropical Medicine.
A cause for concern occurs when a virus mutates by changing the proteins on its surface to help it escape from drugs or the immune system.
“Emerging evidence” suggests that may be starting to happen with the new coronavirus, Trevor Bedford, a biologist and genetics expert at the Fred Hutchinson Cancer Research Center in Seattle, wrote on Twitter.
“We’ve now seen the emergence and spread of several variants” that suggest this, and some show resistance to antibody treatments, he noted.
Will the current vaccines offer protection?
Scientists say there’s no evidence that vaccines being deployed in the UK — made by Pfizer and BioNtech — or other COVID-19 shots in development will not protect against this variant.
“It’s unlikely that this will have anything more than a minor, if any, effect on the vaccine’s effectiveness,” said Adam Finn, a vaccine specialist and professor of pediatrics at Bristol University.
Vallance also said COVID-19 vaccines appeared to be adequate in generating an immune response to the variant of the coronavirus.
“We are not seeing … any gross changes in the spike protein that will reduce vaccine effectiveness so far,” said Julian Tang, professor and clinical virologist at Leicester University.
U.S president-elect Joe Biden’s surgeon general nominee, Vivek Murthy, said Sunday on NBC’s Meet the Press that there’s “no reason to believe that the vaccines that have been developed will not be effective against this virus as well.”
Vaccines produce wide-ranging responses by the immune system beyond just those to the spike protein, several experts noted. The possibility that new strains will be resistant to existing vaccines are low, but not “inexistent,” Dr. Moncef Slaoui, the chief science adviser for the U.S. government’s vaccine distribution effort, said Sunday on CNN’s State of the Union.
“Up to now, I don’t think there has been a single variant that would be resistant,” said Slaoui. “This particular variant in the U.K., I think, is very unlikely to have escaped the vaccine immunity.”
Will current COVID-19 tests detect the new strain?
One of the mutations in the new variant affects one of three genomic targets used by some PCR tests. This means that in those tests, that target area, or “channel,” would come up negative.
“This has affected the ability of some tests to detect the virus,” said Robert Shorten, an expert in microbiology at the Association for Clinical Biochemistry & Laboratory Medicine.
Since PCR tests generally detect more than one gene target, however, a mutation in the spike protein only partly affects the test, reducing that risk of false negative results.