TWO coronavirus variants have merged, scientists say, raising concerns about the course of the virus’ evolution.
The hybrid formed when the Kent and Californian variants combined by infecting one person at the same time.
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Variants that have recently been discovered, including a merged UK and US variant
The Kent strain (B.1.1.7) is more easily spread and deadly, while the Californian variant (B.1.429) has some ability to escape immunity.
This new variant, which has not been named, was detected in a laboratory in New Mexico, according to a report from New Scientist.
It has not yet been found in a coronavirus case in the UK.
It is normal for the virus to evolve over time and scientists say new variants are not unexpected.
There have been thousands of mutations – changes in the viruses genome – since it emerged in 2019, most of which have not had any significance.
But some give the virus better abilities to cause harm, by spreading easier or causing more death.
Some mutations can help the virus dodge antibodies, which causes problems for vaccine efficacy and reinfection.
Dr Simon Clarke, an associate professor of cellular microbiology at the University of Reading, told the Sun: “Mutations are normal, but some of them give us cause for concern. They are not to be dismissed and are serious.”
How did the new variant happen?
When two variants merge together, it is called a “recombinant”.
Dr Clarke explained how they occur: “Two viruses infect the cell, they jumble up the genetic material – called RNA – and produce a new variant.
“You end up with a mosaic – some bits of the genetic code is from virus A, some is from virus B, making virus C.”
Has this happened before?
Dr Clarke said: “It might be the first time these two strains have come together. But we’ve known this since spring of last year so it’s not that surprising.”
It is thought that SARS-CoV-2, the virus that causes Covid-19, was the result of a recombination event in bats.
That’s according to Professor Lawrence Young, a virologist and oncologist at the University of Warwick, who told the Sun: “Recombination events are important for the evolution of coronaviruses.”
He said he expected there is some “very low level” of recombination events to be occurring in humans.
But it has not been reported by the UK’s genomic sequencing scientists at the Covid-19 Genomics UK (Cog-UK) Consortium.
Prof Young said: “I’m surprised we aren’t seeing more recombination. Given the amount of infection in the world, the amount of sequencing we are doing, why are we not seeing more?”
How many cases are there?
It’s not clear at this stage how many people could be infected with this variant.
Scientists only genetically analyse a fraction of coronavirus test samples to look for evidence of new variants, therefore they won’t pick up all the cases.
It has not been reported in the UK so far.
The recombinant was discovered by Dr Bette Korber at the Los Alamos National Laboratory in New Mexico.
It is not clear whether the variant is being transmitted between people or is just a one-off caseCredit: Avalon All rights reserved.
The Californian strain has been blamed for a wave of cases in the Los Angeles area. Pictured: People queue for testing in NovemberCredit: AFP or licensors
She reportedly told a meeting organised by the New York Academy of Sciences on February 2 that she had seen “pretty clear” evidence of it in a database of virus genomes in America.
Dr Korber has only seen it is a singular time out of thousands of cases.
So it is not clear whether the variant is being transmitted between people or is just a one-off case.
The Kent strain has become widespread globally, while the Californian strain has been blamed for a wave of cases in the Los Angeles area.
What is the behaviour of the new variant?
According to New Scientist, the variant carries a mutation from the Kent variant called the 69/70 deletion, and L452R from the Californian variant.
Prof Young said it was difficult to comment on how this variant may behave – including its symptoms, disease severity, and ability to spread – without the data being published.
But he said it was “very strange” that the variant had not picked up all the mutations in both variants.
He said without the total set of the Kent’s mutations, which “bunched together affect transmissibility”, it’s not clear if the new variant would be more easily spread.
Prof Young added: “One thing you can guesstimate is with only this 69/70, it’s very unlikely to be more transmissible than the Kent strain itself.”
What are the different Covid variants in the UK?
SINCE the Covid pandemic erupted last year, there have been various different variants of the SARS-Cov-2 virus detected across the world.
As the virus replicates inside human cells it occasionally makes small copying errors or mutations.
If enough distinct mutations are made and passed on, the result can be new variants.
While scientists say they are normal and were expected, some are more concerning than others. That’s because some mutations – like the E484K mutation – can make vaccines less effective. The mutation affects the spike protein, the bit of the virus that allows it to bind to human cells and infect them.
Here we outline the different Covid variants that have so far been detected in the UK:
- The original Covid virus – this is the variant that was widely circulating in 2020
- The Kent variant (B.1.1.7) – this became the dominant version of the virus just before Christmas
- The South African variant (B.1.351) – this is a variant that cropped up in South Africa and has now been traced in the UK – both in people who have and haven’t travelled to the country. It features the E484K mutation which helps the virus evade vaccines
- The Bristol variant (VOC 202102/02) – this developed from the Kent strain, and now (unlike the dominant Kent strain) features the E484K mutation, helping it escape vaccines too
- The Liverpool variant – this developed from the original Covid virus, and (unlike the original) features the E484K mutation.
- The B.1.525 variant – first detected in Nigeria it has emerged in 10 countries including the UK, and features the E484K mutation
The L452R mutation from the Califronian variant, “we know affects the antibodies to recognise” the virus, Prof Young said.
His suspicion is that L452R will act in a similar way ot E484K.
This mutation, found in the South African and Brazil variants, is known to slightly weaken the current Covid vaccines’ efficacy.
But he reassured that it has always been known vaccines will need be tweaked in the future to deal with new variants.
Should we be worried?
At this stage, the importance of the double variant is unclear.
But Dr Clarke warned: “What we have got is potentially the transmissible variant mixed with an antibody resistance variant. That’s always bad news.
“Anything we see that makes the virus spread more quickly, kill or make people seriously ill – that becomes a ‘variant of concern’.”
There are currently four “variants of concern” in the UK at this stage.
Dr Clarke said the most concerning aspect was that the Kent strain has changed twice now.
The first time was in the UK, after public health officials revealed it had evolved to carry the E484K mutation.
This has caused 22 cases so far, mostly in Bristol.
What does it mean for the course of the pandemic?
Dr Clarke said it would be more worrying if a variant emerged that carried several mutations capable of dodging antibodies – such as the L452R with E484K together.
He said: “The big problem would come about if those mutations that make the virus less sensitive to antibodies accumulated in one variant.
“That’s not happened yet, that we know of.”
Prof Young agreed and said in the short-term, there isn’t too much to be worried about.
He said: “If we step back a little bit, and see the level of infection in the country, the levels of infection are coming down quite drastically which is a good thing.
“That’s not consistent with there being a more rampant variant spreading in the community. But that doesn’t mean there are not hotspots in England.”