Researchers in the US and Britain studied the viruses taken from patient samples and found that the West seems to have been hit by a mutated version of the original.
They said the mutated form of the virus appears more infectious and spreads faster but it does not seem to affect how seriously ill someone becomes.
It also raises the prospect that the virus is able to mutate in a way that could – over time – lead to fundamental chances which reduce the likelihood of natural immunity of the effectiveness of a vaccine.
Believed to have originated in China or Europe the version of the virus, dubbed G614, is now ‘the dominant pandemic form in many countries’, the scientists said.
They said it was first found in Germany in February and had since become the most common form of the virus in patients worldwide – it appears to force out the older version whenever they clash.
Viruses mutate naturally all the time and it is not usually cause for alarm but should be studied in case they change so much they become unrecognisable to the body and immunity from a first infection cannot protect against them, as is the case with flu.
The research comes as British scientists today revealed in a Government study that there were at least a dozen different strains circulating in the population in March.
The newer strain named G614 (blue) appeared later on in the pandemic but, since then, has dominated the older, slower-spreading strain D614 (orange) in most areas of the world. It was the only one recorded in England but all the patients sampled were taken from one city – Sheffield
Most countries outbreaks began with the older D614 strain (shown in orange). In China and Singapore this remained the dominant strain but in most countries worldwide it was edged out in March by the mutated G614 version
The study was done by scientists at the University of Sheffield and Los Alamos National Laboratory, New Mexico, and published openly online.
It focused on a mutation of the virus, officially named SARS-CoV-2, which was referred to as D614G. The researchers referred to the viruses without the mutation as D614 and the version with it as G614.
It is not clear whether they classify as separate strains because the mutation is so small and affects only one tiny part of the virus.
Looking at samples from around the world they found that D614 appeared to have been the virus’s original state in humans, and the one found in Wuhan.
It made up the vast majority of all COVID-19 infections in China, and Asia as a whole, and also seemed to be the first version of the virus to appear in the countries they studied.
However, the mutated version – G614 – started to appear soon after in Europe and North America in particular, before going on to take over as the dominant virus.
‘A clear and consistent pattern was observed in almost every place where adequate sampling was available,’ the researchers said.
‘In most countries and states where the COVID-19 epidemic was initiated and where sequences were sampled prior to March 1, the D614 form was the dominant local form early in the epidemic.
‘Wherever G614 entered a population, a rapid rise in its frequency followed, and in many cases G614 became the dominant local form in a matter of only a few weeks.’
They said the G614 mutation may give the virus a ‘selective advantage’ which makes it better able to bind to cells in the airways, or to shed viruses which it uses to reproduce and spread.
It could do this because the D614G mutation appeared to affect the shape of the ‘spike’ protein that the virus uses to attach to a person’s cells and infect them.
A sample of 447 hospital patients in Sheffield showed that people had a higher viral load when infected with G614, meaning they had a higher quantity of viruses circulating in their body.
This could make them more likely to spread COVID-19 because they could be more likely to show symptoms and have more viruses on their breath, for example.
The researchers wrote: ‘An early April sampling… showed that G614’s frequency was increasing at an alarming pace throughout March, and it was clearly showing an ever-broadening geographic spread.’
And they added: ‘Through March, G614 became increasingly common throughout Europe, and by April it dominated contemporary sampling.
‘In North America, infections were initiated and established across the continent by the original D614 form, but in early March, the G614 was introduced into both Canada and the USA, and by the end of March it had become the dominant form in both nations.’
The researchers added that the fact that the spike protein is such a key target for vaccines and medication, means that this apparent evidence it can mutate was cause for concern.
If a vaccine is developed to target the virus by latching onto its spike protein, for example, that would become useless if the protein changed shape.
And the same principle applies to natural immunity – if the body learns to attack viruses with a spike protein that is one shape, it may not recognise or react to a virus with one that takes a different form.
Dr Jonathan Stoye, from The Francis Crick Institute, said: ‘Although the functional significance of the changes observed have yet to be fully characterised, the study shows that SARS-CoV-2 can alter its genetic structure in multiple ways as it spreads around the world, a finding likely to have important implications for vaccine development.’
Scientists are still not sure whether people develop long-term immunity after their first bout of COVID-19.
Sir Patrick Vallance, the UK’s chief scientific adviser, said it is very unlikely that people would develop total protection after recovering from the illness.
Although the older D614 strain (orange) managed to remain dominant in Asia for most of the pandemic, it was quickly superseded by the mutated version in Western countries and Africa, which started recording outbreaks later on
The Sheffield research comes as SAGE, the British Government’s Scientific Advisory Group for Emergencies, today published a paper revealing that at least a dozen strains of the coronavirus were circulating in the UK in March.
It is not clear whether G614 is included in this research.
The scientists who did that study used different names for the strains they studied, and the research was done earlier than the G614 study.
In it, leading genetic scientists had analysed the genomes of the killer virus in 260 infected patients from all corners of the UK.
They say they identified 12 unique versions of the virus, one of which has only ever been found in Britain – meaning it mutated on UK soil.
But the COVID-19 Genomics UK Consortium (COG-UK) said the number of strains ‘is very likely substantially higher’ due to under-sampling in the UK.
The scientists say most of the strains were imported from Italy and Spain, the worst-hit countries in the world at the time the research was carried out.
There is no suggestion that any of the strains are any more potent or infectious than another, infectious disease experts say.
Professor Paul Hunter, at the University of East Anglia, told MailOnline it is ‘entirely plausible’ this could happen to one of the strains if it continues to evolve.
The report, made public today, was given to the Government’s Scientific Advisory Group for Emergencies (Sage) in March to help them map the outbreak’s spread.
Other secret documents of scientific evidence that helped shape the Government’s response to the crisis were released today.
There are at least a dozen different strains of coronavirus ravaging the UK. The most common is the B.12.1 strain (pink) and the B.11 strain (green). The researchers did not make clear which strains were imported from other countries, nor did it disclose which one is unique to Britain
New mutation of COVID-19 suggests the disease is weakening
Scientists have discovered a unique mutation to coronavirus in Arizona – and it’s a pattern that they’ve seen before.
One of the 382 samples they collected from coronavirus patients in the state was missing a sizeable segment of genetic material.
In the middle and late stages of the SARS epidemic of 2003, this very same kind of deletion started cropping up in patients around the globe.
It’s not just any mutation – the change robs the closely related viruses of one of their weapons against the host’s immune response, making the infection weaker.
As that mutation became widespread, the SARS outbreak wound down. By July – five months after it emerged in Asia in February 23 – there were no new cases, and the outbreak was considered contained.
Now, Arizona State University experts have only found one person who had a version of the virus with this mutation – but they say if genome sequencing for coronavirus become more common, we may find far more.
They sequenced the genomes of the virus in 382 nasal swab samples. Like ours, viral genetic material is composed of chemical units known by their letters.
The human genome consists of three billion DNA ‘letters’. Viral genomes are far simpler than ours, and coronavirus consists of 30,000 letters of RNA.
In one of the samples they collected, the ASU researchers discovered that a massive 81 letters were missing. And these were a particularly meaningful missing 81 pieces of RNA.
‘This is something we’ve seen before in the 2003 SARS outbreak during the middle and late phase of the outbreak, the virus acquired large deletions in these SS3 proteins,’ lead study author Dr Efrem Lim told DailyMail.com.
‘These proteins are not just there to replicate – they are in there to help enhance virulence and suppress the immune system [of the host]. It evolved with a more attenuated from in the late phase of the epidemic.’
In other words, the SARS virus changed to be weaker (attenuated viruses are less the less risky, modified versions researchers make in labs as the basis for vaccines) as time went on.
And now, at least one sample of SARS-CoV-2 had done the same.
The researchers did not make clear which strains were imported from other countries, nor did it disclose which one is unique to Britain.
All viruses mutate slightly as they spread through populations, which leads to small changes in their genetic material.
Scientists say the virus does this to overcome immune system resistance in different communities.
As part of the study, COG-UK researchers analysed patients in Belfast, Birmingham, Cambridge, Cardiff, Edinburgh, Exeter, Glasgow, Liverpool, London, Norwich, Nottingham, Oxford and Sheffield.
They found 12 unique strains, most of which had been imported from Europe. The report did not specify which countries, but said the majority of cases came from Italy. It found that strains had also come from China, the US and Australia.
Professor Hunter told MailOnline: ‘There are a number of issues with these strains – are they likely to cause different severity of disease? Are they likely to be more infectious? And are they capable of invalidating vaccines?
‘The answer to all three of these is that we have no idea. There is no suggestion from this study – or any other that I have read – that show these strains are more virulent or infectious that one another.
‘But it is plausible that one strain could mutate to the point where people with antibodies to an older strain are no longer immune to it.
‘These are called escape mutants, because they escape from the control of immunity.
‘It happens with influenza a lot. The current coronavirus does not seem to do this as fast, though, but it is plausible down the line.’
Professor Hunter said the main value of the report was that it helps scientists track the spread of the infection around the UK.
He said this would become crucial when easing out of lockdown.
Professor Hunter added: ‘This enables researchers to continue to track where it’s going and help enforce new rules to stop another outbreak.
‘Say you have a cluster in the north west of England, which is unexpected, and it is the same strain found predominantly in London, then you could see that is must’ve been spread by someone travelling from the capital.
‘You could use this to tell if someone had broken lockdown rules by travelling there, or you could close down a possible transmission passage [a train line, for example].’
Sir patrick Vallance told MPs: ‘But a lot of the cases in the UK didn’t come from China and didn’t come from the places you might have expected’
The COG-UK is an innovative partnership of NHS organisations, the four Public Health Agencies of the UK, the Wellcome Sanger Institute and more than 12 academic institutions, including Cambridge University.
It is supported by £20million funding from the UK Department of Health and Social Care (DHSC), UK Research and Innovation (UKRI) and the Wellcome Trust.
Coronavirus has mutated to become deadlier in Europe, Chinese study claims
There could be as many as 30 different strains of coronavirus, a study of patients in China has claimed.
Zhejiang University scientists studied a small number of patients with the disease and uncovered tens of mutations – 19 of which had never been seen before.
Some mutations boosted the virus’ ability to invade cells in the body, others helped the disease multiply more rapidly.
The most deadly strains were genetically similar to the ones that spread in Europe and in New York, reported the South China Morning Post.
Meanwhile, the weaker strains were similar to those found circulating within other parts of the US, such as Washington State.
The authors say their findings – based on just 11 patients – are the first to show the mutation could affect the severity of illness.
They believe the previously unreported mutations could be the reason behind Europe and New York’s devastating death tolls.
It is still unclear why the aggressive strain of COVID-19 spread to Europe and the more mild version hit large swathes of the US.
But scientists say viruses are constantly mutating to overcome immune system resistance in different populations.
It comes on the heels of studies that claim the US was hit by two different clusters of the coronavirus, with type A dominating the West Coast and the deadlier type B in New York.
Experts say the type A outbreak was spread to the US from China, where as the crisis in New York likely came from Europe – which was also rocked by type B.
For the latest study, published on the pre-print service medRxiv.org, the team analyzed viral strains from 11 Chinese coronavirus patients.
The team, conducted by Professor Li Lanjuan and colleagues, tested how effectively the virus could infect and kill human cells in the laboratory.
Viral load – the amount of the virus – was assessed in all the cells after one, two, four and eight hours, as well as the next day and 48 hours later.
And the experts also looked at the cytopathic effects – whether the virus structurally changed the cell during infection – up to three days after the experiment.
The most aggressive strains created up to 270 times as much viral load as the least potent type, according to the results.
And the strains that produced the highest viral load led to a ‘higher cell death ratio’, Professor Li and her team revealed.
Writing in their paper, the team said: ‘Our results show the observed mutations can have a direct impact on the viral load and CPE.
‘This finding suggests the observed mutations in our study… can significantly impact the pathogenicity (the ability to cause disease) of SARS-CoV-2.’
The team found some of the deadliest mutations in Zhejiang, where the university is located.
These mutations had also been seen in several hard-hit European countries such as Italy and Spain – before spreading to the US epicenter New York.
However, some of the milder mutations were the varieties largely found in the US, including Washington state, which could be the strain that shut down Wuhan, where the virus originated.
But the scientists admitted that the ‘full mutational diversity of the virus in Wuhan in the early days is still unknown’.
It comes as damning new figures revealed today that Britain quarantined just 273 out of 18.1million people who arrived in the UK in the three months before the coronavirus lockdown.
The occupants of three flights from the outbreak ground zero in the Chinese city of Wuhan and another bringing home passengers from a cruise ship of Japan were the only ones taken to secure facilities in the UK.
But millions more entering the UK between the start of 2020 and March 22 were able to enter freely and only advised to self-isolate, according to figures obtained by the Guardian.
It came as it also emerged the UK suffered a ‘big influx’ of coronavirus from arrivals from Italy and Spain who were not quarantined.
Mapping of the Covid-19 genome shows that UK cases come from all over the world, chief scientific adviser Sir Patrick Vallance told MPs.
But a large number of cases in early March were from Europe and ‘seeded right the way across the country’ because Brits arriving back in the UK were allowed to return home.
Giving evidence to the Health and Social Care Committee this morning, Sir Patrick said that experts on the Scientific Advisory Group for Emergencies (Sage) had advised ministers they would have to be ‘extremely draconian’ in blocking travel from whole countries otherwise ‘it really was not worth trying to do it.’
‘Whether that was people returning from half-term, whether it is business travellers or not, we don’t know,’ he told MPs.
‘But a lot of the cases in the UK didn’t come from China and didn’t come from the places you might have expected.
‘They actually came from European imports and the high level of travel into the UK around that time.’
At the weekend a senior minister finally confirmed visitors to the UK could face time in quarantine as the Government ‘actively’ considers stronger anti-coronavirus measures at the borders.
Transport Secretary Grant Shapps said that new arrivals could also be forced to download a new contract app onto their smartphone as a condition of entry.
New restrictions would make the UK one of the last countries to introduce them, with the country very much an outlier in recent weeks by not halting inbound flights or insisting arrivals are checked.
People arriving are currently advised to self-isolate but there is no enforced testing.
Home Secretary Priti Patel is believed to be among those who have demanded tougher rules for foreign visitors and the remaining Brits still abroad who make it home.
But Sir Patrick suggested stopping travel was of limited use unless action was taken against a wide-range of countries.
‘What was very clear, and I think you can see this now in retrospect, is that the idea that you can control this by stopping travel from one place doesn’t work unless it is of course the only source of import,’ he said this morning.
‘We have now in the UK sequenced 13,6000 viral genomes, we got imports from all over the place.
‘So quite early on the advice Sage gave was ”if you are going to do something on travel you either need to be extremely draconian – stop all travel from all sorts of countries – or it is really not worth trying to do it, trying to stop from one place because you won’t make it happen”.
‘So I think the answer is not, unless the country chose to do that, stopping travel anywhere and to … make sure that as people come back you have appropriate systems to isolate and make sure they are following the same rules as the rest of the country.’
Deputy chief medical officer Dr Jenny Harries, who was also giving evidence, added: ‘There are pros and cons which are not necessarily always obvious I think, between managing influx and outflux of passengers but also goods.
‘If you shut travel routes in, you are also shutting routes for various products which may be essential, not just for our population but all around the world.
‘At the moment most people who are coming back are coming back into the UK back home and they will immediately fall under social distancing regulations anyway.’