One in 10 coronavirus cases in London over the past few weeks has been caused a new strain of the virus, an expert has claimed.
Speaking to BBC Radio Norfolk, Dr Andrew Page was asked about the prevalence of the new variant which was revealed by Matt Hancock on Monday.
Dr Page, the head of informatics at Norwich's Quadram Institute, said the strain had played a large role in sharp rises in infection rates in London and East Anglia.
“Mutations happen all the time,” Dr Page said, “We first saw this lineage a few weeks ago in Wyndham and it has expanded now within Norfolk to be around 20% of all positive strains that we sequence.
Watch: New coronavirus strain causing sharp rise in cases in London
“And if you compare that to London there’s only about 10% of cases that have this lineage. So it’s a bit of a problem but we don’t really know what it does or if it’s worse than normal.”
Asked how new strains of the virus arise, Dr Page said the changes happened rapidly and were usually “nothing to worry about”.
“These changes happen all the time, we’ve tracked thousands of these. It’s not something to worry about, it just does happen. And hopefully this change isn’t a problem.
Asked why the new strain would be particularly prevalent in counties such as Norfolk, he said it had “exploded out of nowhere”.
“It wasn’t around in October so it has kind of exploded out of nowhere,” Dr Page added.
“It is a little bit higher in Norfolk but then if you look at Suffolk the county’s neighbour, that’s only about 3% prevalence so it’s quite low there.
“So it just kind of varies depending on what has been spreading around locally in the community.”
On Monday, Hancock said higher infections in the South East may be in part due to a newly-detected variant of coronavirus which is growing faster than the existing one.
Public Health England (PHE) said that as of December 13, 1,108 cases with this new variant had been identified, predominantly in the south and east of England.
But experts such as Calum Semple, professor of outbreak medicine at the University of Liverpool and a member of the Scientific Advisory Group for Emergencies (Sage), said it is normal for viruses to mutate.
Prof Semple told BBC Breakfast: "People should not be losing sleep about this, they really need to leave the virology to the scientists because we're at the very early stages of understanding what's going on here.
"What I can say is that coronavirus, like many other viruses, mutate all the time.
"And without the presence of community immunity - that's because we don't have herd immunity and won't have for many, many months - the virus essentially is free to change and become more comfortable with the humans with which it is living.
"That's what the virus is doing - it is learning how to become slightly better at living with us and becoming slightly more infectious. But that does not mean it's harming us more or causing more severe illness in people."
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