Health

Up to HALF of Covid survivors 'may still be vulnerable to South African variant'


The South African coronavirus variant may slip past parts of the immune system in as many as half of people infected with different versions in the past, scientists fear.

Researchers say that a mutation on a specific part of the virus’s outer spike protein appears to make it able to ‘escape’ antibodies. Antibodies are substances made by the immune system that are key to destroying viruses or marking them for destruction by white blood cells. 

South African academics found that 48 per cent of blood samples from people who had been infected in the past did not show an immune response to the new variant. One researcher said it was ‘clear that we have a problem’.

Professor Penny Moore, the researcher behind the project, claimed people who were sicker with coronavirus the first time and had a stronger immune response appeared less likely to get reinfected.

Antibodies are a major part of the immunity that is created by vaccines – although not the only part – so if the virus continues evolving to escape from them it could mean that vaccines have to be redesigned and given out again. 

But experts so far say they have no reason to believe vaccines won’t work, which may be because they produce a stronger immune response than a very mild infection, and because they produce various different types of immune cells. 

At least 54 people in the UK have already been confirmed to have had the South African Covid variant, although these were picked up by random sampling so the true number is likely much higher.

In a bid to stop new variants coming into the country, Britain has now made it mandatory for all international arrivals to quarantine for 10 days and provide proof of a negative test within three days before departing for the UK. 

All three of the mutated versions of the coronavirus found in recent weeks – the ones from Kent, South Africa and Brazil – have had a change on the spike protein of the virus called N501Y, which scientists say makes it better able to latch onto the body and spread

The new variants of the coronavirus have mutations on the spike protein, which are key for the immune system’s antibodies to latch onto and destroy it. Changing the shape of them makes it harder for the body to catch the virus

Professor Penny Moore, from the National Institute for Communicable Diseases in South Africa, found in a small study of 44 people that 48 per cent of them (21) had no immune response at all to the new variant despite having had coronavirus before

Professor Penny Moore, from the National Institute for Communicable Diseases in South Africa, found in a small study of 44 people that 48 per cent of them (21) had no immune response at all to the new variant despite having had coronavirus before

Researchers have been scrambling to find out more about concerning new variants of the coronavirus since major changes were found in strains coming from Kent in England, South Africa and Brazil.

The virus appears to be evolving to transmit around 50 per cent faster and to get past some antibodies made in response to other variants of the virus.

Antibodies are extremely specific, fitting to the virus like a key in a lock, and are moulded to the virus when it is in the body. If the virus changes too much, the old antibodies may no longer be able to fit to it and so can’t destroy it. 

This means people infected with the virus three months ago or more may not have total natural immunity if they catch a newer version. 

A study by the University of Washington looked at how the blood of people with antibodies for an older version of coronavirus reacted to the new variant. 

In a group of 11 blood samples, nine of them showed ‘reduced binding’ from antibodies when exposed to the key mutation on the South African variant.

The mutation they studied is called E484K, which changes the shape of the spike protein that the virus uses to latch onto cells in the body. The same mutation has also been spotted in both Brazilian variants.

The most cases of the South African variant - called B.1.351 - have been detected in the UK and South Africa. But scientists say the UK has found so many because it sequences many samples

The most cases of the South African variant – called B.1.351 – have been detected in the UK and South Africa. But scientists say the UK has found so many because it sequences many samples

The report from COG-UK also revealed the first cases were spotted back in October last year

The report from COG-UK also revealed the first cases were spotted back in October last year

Dr Jesse Bloom and colleagues wrote: ‘The site where mutations tend to have the largest effect on binding and neutralization is E484, which unfortunately is a site where mutations are present in several emerging SARS-CoV-2 lineages. 

‘However, some [samples] are more affected by mutations at other sites, while others are largely unaffected by any single mutation.’ 

Data from researchers in South Africa, where the variant emerged, appears to suggest that immunity to Covid-19 was reduced in more than 90 per cent of people when they were reinfected with the new variant.

Professor Moore, from the National Institute for Communicable Diseases in South Africa, found in a study of 44 people that 48 per cent of them (21) had no immune response at all to the new variant despite having had coronavirus before.

She told a scientific panel meeting yesterday: ‘When you test the blood of people infected in the first wave and you ask “Do those antibodies in that blood recognise the new virus?” you find that in 50 per cent of cases – nearly half of cases – there’s no longer any recognition of the new variant.

‘In the other half of those individuals, however, there is some recognition that remains. I should add those are normally people who were incredibly ill, hospitalised and mounted a very robust response to the virus.’

Professor Moore said that research made it ‘clear that we do have a problem’, but that it is still in its early stages and laboratory studies cannot perfectly recreate the real world.

On whether vaccines would be affected, she added: ‘If you have very high antibodies to begin with, there does remain some recognition of the new virus and that’s important as we think about vaccines.

LIFTING LOCKDOWN TOO SOON COULD ALLOW MORE MUTATIONS

Britain must keep Covid under wraps during the vaccine roll-out or it risks allowing the virus to mutate and render the jabs useless, an expert has warned.

Dr Christina Pagel, a health and mathematics researcher based at University College London, said allowing the virus to continue to spreading could give the coronavirus more time to mutate in a way that would make vaccines stop working. 

The UK is already on high alert for mutations and today closed its borders to anyone who has not tested negative within 72 hours of travelling, to stop evolved variants coming in.  

But there is still a risk that people will slip through the checks and that outbreaks will start again inside the country in the spring – vaccines minister Nadhim Zahawi has suggested lockdown rules could start to be lifted as soon as March.

If the virus can keep circulating it will keep mutating and, the longer this goes on for, the more likely it is that a devastating mutation will emerge. Scientists fear the virus could learn to evade vaccines and natural immunity over time. 

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Britain’s second wave was driven by a highly infectious variant that first emerged in Kent.

Laboratory researchers have also spotted dozens of cases of a South African variant across the UK and last week confirmed 11 samples had tested positive for one of two Brazilian variants.

England’s chief medical officer Professor Chris Whitty has already admitted that the UK’s current strategy of half-vaccinating people raises the risk of the virus mutating to become vaccine-resistant.

Dr Pagel claimed a combination of rapid vaccination and stringent ‘suppression’ of outbreaks should continue until the majority of people have been immunised.

‘Some vaccines elicit very high levels of antibodies and others do not, so we need to understand whether there is some recognition by vaccine-elicited, rather than infection-elicited, antibodies.’

The studies by Dr Bloom and Professor Moore have not yet been reviewed by other scientists and published in journals and are known as ‘pre-print’ papers.

Scientists tracking the South African variant in the UK yesterday confirmed that at least 54 Brits have tested positive for it so far, with the first case dated back to October 2020. 

It’s likely that there have been far more cases of the variant because the Covid-19 Genomics UK Consortium (COG-UK) only analyses 10 per cent of random positive coronavirus samples. 

COG-UK say they’ve not found any evidence yet that it will make the current wave of vaccines less potent. 

In their 41-page report, COG-UK said tests had already been carried out on the South African variant which established some of its mutations did not lessen the effectiveness of the vaccine.

But they added that not all of the mutations were checked that are found on the rapidly spreading strains in the UK, South Africa and Brazil. 

In a scientific study published as a pre-print on medRxiv, the scientists describe the genetic make-up and spread of the South African strain.

‘This lineage emerged in South Africa after the first epidemic wave in a severely affected metropolitan area, Nelson Mandela Bay, located on the coast of the Eastern Cape Province,’ they wrote.

‘This lineage spread rapidly, becoming within weeks the dominant lineage in the Eastern Cape and Western Cape Provinces.’

They added: ‘While the full significance of the mutations is yet to be determined, the genomic data, showing the rapid displacement of other lineages, suggest that this lineage may be associated with increased transmissibility.’ 

It comes after Dr Christina Pagel, who is part of the Independent SAGE group, which has been highly critical of the Government’s pandemic response, told The Times: ‘We know that this virus does mutate and it mutates in ways that can potentially evade the vaccine.

‘Once we start vaccinating, we really want to vaccinate everybody before it starts to have the opportunity to mutate because then you’re much more protected…’

‘What you don’t want is to get to September and suddenly you’ve got a new variant – whether we’ve imported it from somewhere else or we’ve grown our own variant – and then you’ve vaccinated 40million people and you have to start from scratch.

‘I just can’t imagine anything worse. So that’s why I think you actually want to go for suppression now.’ 

Coronavirus, like all pathogens, is constantly evolving as it spreads. But most of these changes make no difference to the virus or the way it behaves.

COG-UK said yesterday that over 700 individual mutations have been spotted so far in the coronavirus in Britain. 

But, rarely, the bug will mutate in a way that gives it an evolutionary advantage – such as being able to spread easier or reinfect people who have previously caught and beat an older version of the virus.   

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There have been at least two reports of nurses in Brazil becoming reinfected with new strains there, despite having natural immunity from the first wave in spring.

Even though reinfection has not been proven on a large scale, the UK Government is keen not to take the chance and has introduced sweeping travel restrictions for anyone entering the country. 

Dr Pagel has warned that letting the virus spread too much during the vaccine roll-out will give it more opportunities to mutate.

Vaccines have been developed to create immune responses to target the spike proteins of the virus.

Mutations that occur on the spike may make the protein unrecognisable to the immune system, and therefore allow the disease to slip past. 

Some scientists have warned that giving people half-doses of vaccines – which the UK is doing to stretch its limited supplies to cover more people – could expose the virus to low levels of the immune cells that are supposed to destroy it.

If this happens often and the viruses find they can get past the weak immune response, scientists fear this could lead to a version of the virus that can keep spreading even in vaccinated people. 

Professor Chris Whitty admitted this month: ‘That is a real worry but quite a small real worry within the system.’

‘The general view was the size of the increase of the risk is sufficiently small that, measured against this ability to double the number of people who actually are vaccinated, the public health arguments are really strongly for doing what we have decided to do.’

He added: ‘Clearly, if we had infinite vaccine we might have taken different approaches, but we don’t.

‘At this point in time, for the next three to four months, the number of vaccines we have available is going to constrain our ability to get through the 25 to 30 million people we must do.

‘Whilst this is such a fast-moving virus at this time, our view was very strongly, on the balance of risk, the benefits to the UK for us at this point in the epidemic were in favour of doing this.’

The coronavirus is expected to mutate eventually in a way that will make vaccines less effective, but scientists aren’t yet sure when or how drastic this will be.

It could mean that people will be vaccinated every year, as with flu.

NHS England medical director, Professor Stephen Powis said that it was likely that there may need to be ‘frequent, maybe annual’ vaccination programmes to deal with new variants of Covid-19.

He told BBC Breakfast: ‘The early signs are that the vaccines will be perfectly adequate for that new strain.

‘Other strains of the virus will emerge – that’s what happens with viruses, they mutate.

‘Every year flu is a little bit different and we adapt our flu vaccines each year to cope with that.

‘I think it’s perfectly possible that over time the Covid vaccine will need to be adapted from year to year to deal with new strains.

‘The good news is that we’re using new technology with these new vaccines and that can be done very quickly.

‘So yes it is likely that there may have to be frequent, maybe annual – like flu vaccine programmes, which will deal with these new variants, but it’s a bit too early to be absolutely sure yet.’



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