Pfizer's Covid vaccine 'will work against South African variant'
Pfizer’s Covid vaccine WILL work against South African variant and boost protection for people who have already had the virus, study suggests
- Blood of people who had Pfizer/BioNTech jab still able to neutralise coronavirus
- The protection stronger than that of someone who had different version of virus
- But weaker than vaccine would be against older variants, with fewer antibodies
- Comes amid fears Oxford/AstraZeneca will only give ‘minimal’ protection
- Only 149 cases of South Africa variant found in the UK so far, PHE says
Pfizer’s vaccine will work against the South African Covid variant, a study has found, although its mutations ‘could render some individuals less well protected’.
Researchers at New York University tested how well the variant of the virus could be destroyed by the blood of 10 people who had received Pfizer’s jab.
They found the immune antibodies made by the vaccine were still able to neutralise – destroy – the coronavirus, but the body didn’t make as many of them.
While antibody levels would be still high enough to fend off Covid-19 in most people who had the vaccine, and they offered more protection than in people who had had the illness already, they did not work as well as they would on older versions of the virus.
The study was published yesterday in the wake of an alarming study that claimed Oxford and AstraZeneca’s vaccine only offers ‘minimal protection’ against mild cases of the variant.
Britain has been hit by a new wave of fears of extended lockdowns after it emerged that its staple Covid vaccine, of which it’s believed to be receiving two million doses per week, will be rendered less effective by the mutated variant, which is spreading.
Although only 147 cases of the South African variant have been confirmed by Public Health England, experts warn this is just the ‘tip of the iceberg’ and the true number could be 10 or 20 times higher.
Dr Mike Tildesley, a Warwick University infectious disease expert and member of the SAGE advisory board, said the news about Oxford’s jab could have ‘significant implications’ for plans to end lockdown in the UK, suggesting it could be postponed.
The New York University study comes after Pfizer and BioNTech did their own research and found their jab would work against the variant, although Cambridge University scientists cast doubt over whether a single dose would be protective.
Pfizer and BioNTech’s vaccine is one of just two jabs being used in the UK, alongside the one made by Oxford University and AstraZeneca
Delaying the second dose of the Pfizer coronavirus vaccine could leave some elderly patients vulnerable to the South African Covid variant, research suggests.
Laboratory tests by Cambridge University found that a single shot of the jab might not stimulate a strong enough immune response to kill the new strain in over-80s.
Antibody levels only appeared to be protective after a second dose — but the researchers admitted the jab is still likely to be ‘less effective’ when dealing with the E484K mutation on the South African variant’s spike protein.
Experts believe the mutation — which is also present in the Brazilian Covid variants — helps the strain ‘hide’ from the body’s natural defences.
The news is particularly worrying as the UK Government has this week warned that cases of the South Africa variant are cropping up in people who haven’t travelled there, and the same E484K mutation is also appearing on unrelated cases caused by the Kent variant and even older versions of the virus.
Top Government advisers and vaccine manufacturers insist the current crop of jabs should still work against the variant – when given in the full two doses – because the antibodies they make can still stop the disease from taking hold in the body.
Antibodies — disease-fighting proteins created by vaccines and in response to previous infection — are also not the immune system’s only layer of defence.
Scientists reacting to the findings said now was ‘a good time to switch’ away from Britain’s one-dose strategy, which aims to get wider vaccine coverage quicker.
Regulators pivoted from their original plan to give people their second dose after 21 days when the Oxford University/AstraZeneca vaccine was approved at the end of December.
They pushed back the second dose for 12 weeks in a bid to give partial protection to as many vulnerable people as possible and drive down hospital admissions. And the strategy has been extremely successful, with 9.6million people now vaccinated with at least a single dose of either Pfizer’s or AstraZeneca’s jab.
No10 has already launched an effort to swab tens of thousands people in areas of England where cases of the South African variant have been discovered in people who haven’t travelled out of the country.
The New York University researchers, led by microbiologist Dr Nathaniel Landau, wrote: ‘The findings suggest that the protection provided by vaccination will remain largely intact against the South Africa variant and other currently circulating SARS-CoV-2 variants.’
The way the scientists tested the vaccine was by exposing different variants of the virus to the blood of people who had had the jab and those who hadn’t.
Watching the reactions between them can then show how well different types of immunity destroy the virus and which ones don’t.
When someone is vaccinated they develop immune proteins called antibodies that are extremely specific to the virus included in the vaccine and, if the immune system is faced with a different version of the virus in the future, it may be less able to stop it.
If the virus mutates to look different, those antibodies will latch onto the virus less often, meaning more of the coronavirus can slip through and the risk of illness increases.
Pfizer’s vaccine was found to be around 95 per cent effective at preventing illness caused by the old variant of coronavirus but this efficacy will now be lower because the people who developed weaker immunity may now not have enough.
The jab still worked against the Kent variant, B.1.1.7, they said.
But it was less effective against a key mutation named E484K on the South African variant, which is known as B.1.351.
Dr Landau and colleagues said: ‘These findings suggest that antibodies elicited by primary infection and by the [Pfizer/BioNTech] vaccine are likely to maintain protective efficacy against B.1.1.7 and most other variants but that the partial resistance of virus with the B.1.351 spike protein could render some individuals less well protected, supporting a rationale for the development of modified vaccines containing E484K.’
Their recommendation that companies make vaccine boosters to deal with the new variant, and more that might come in future, is already being followed by some companies.
Oxford and AstraZeneca said last week that their second top-up jab would be ready by autumn this year.
Moderna has already committed to making an updated version of its vaccine to cope with mutations that make the original jab weaker.
Pfizer and BioNTech are understood to also be working out how they could improve their vaccine.
Concerns are now bubbling up that Britain could face longer tougher lockdown rules if the South African Covid variant becomes more widespread.
SAGE’s Professor Mike Tildesley said the discovery about the Oxford jab could have ‘significant implications’ on Britain’s lockdown-easing plans.
He told the BBC Radio 4 Today programme: ‘It means that even with high levels of vaccination there will be a lot of people that could potentially get infected and could potentially pass it on and it may mean that more restrictions might be needed for longer if we cant get on top of this.’
Despite the concerning new finding, one of South Africa’s top infectious disease experts said today the Oxford jab should still protect against severe disease.
Professor Salim Abdool Karim, head of the country’s Covid response unit, pointed to the trial of Johnson and Johnson’s jab, which uses the same technology as Oxford’s and was shown to be 100 per cent effective at stopping Covid hospitalisations and deaths.
And UK ministers have urged Brits to keep faith in the British-made vaccine. Health minister Edward Argar urged the public not to lose sight of the main purpose of vaccines – which is to drive down hospital admissions and deaths to manageable levels.
The comments were echoed by vaccines minister Nadhim Zahawi last night, who said preventing severe disease was the ‘vitally important’ factor for the vaccines.
Professor Mike Tildesley (left), an infectious disease expert and member of the Sage advisory panel, said Britain could face more lockdown restrictions if the South African Covid variant continues to spread. UK health minister Edward Argar (right) urged the public not to lose sight of the main purpose of vaccines – which is to drive down hospital admissions and deaths to manageable levels
Government sources said last night that there was ‘no indication’ the easing of lockdown would be affected by the findings that the Oxford vaccine is less effective against the South African variant.
Mr Zahawi highlighted the low levels of the South African variant means it is unlikely to overtake the Kent one and become the dominant strain in the UK any time soon.
A tweaked version of the Oxford vaccine that targets the new strain is already in development and should be ready by August. The current vaccine rollout should buy jab-makers time until the new booster shots are available.
Mr Argar said this morning there was ‘no evidence’ that the Oxford/AstraZeneca vaccine is not effective at preventing severe illness from coronavirus.
He told Sky News: ‘There is no evidence that this vaccine is not effective in preventing hospitalisation, severe illness and death, which is ultimately what we’re seeking with these vaccines.’
The minister noted that the ‘dominant strains in this country are not the South African strain’, with ‘only a small number of cases of that’.
He added that South Africa’s suspension of the rollout of the vaccine is only ‘temporary’ at this stage.
The study that found the Oxford jab had a ‘minimal effect’ in protecting against mild disease caused by the variant involved 2,000 volunteers, most of whom were young and healthy with an average age of 31.
The study also appeared to show that the South African mutations will allow for ongoing transmission of the virus in vaccinated populations.
Out of 865 people vaccinated with two doses of the Oxford vaccine, 19 contracted the new variant, and out of 884 in the group given a placebo, 23 contracted the disease. Two thirds of the cases were of mild illness, and one third moderate. There were no severe cases.
The researchers also found that previous infection with ‘original’ coronavirus did not protect against contracting the South African variant.
Oxford University said the study did not assess levels of protection against moderate to severe disease, hospital admission or death because the target population was at such low risk.
A spokesman for AstraZeneca said: ‘We do believe our vaccine will still protect against severe disease, as neutralising antibody activity is equivalent to other Covid-19 vaccines that have demonstrated activity against more severe disease, particularly when the dosing interval is optimised to eight to 12 weeks.’
The spokesman added that other immune responses, such as T-cell responses, may have a role in protecting against disease, and initial data suggests these may stay the same with the variant.
Professor Robin Shattock, who is leading Covid-19 vaccine research at Imperial College London, urged caution about the study’s findings.
‘It’s a very small study with just over 2,000 people,’ he told BBC Breakfast.
‘But it is concerning to some extent that we’re seeing that it’s not effective against mild or moderate disease.’
Professor Andrew Pollard, chief investigator on the Oxford trial, said: ‘This study confirms that the coronavirus will find ways to continue to spread in vaccinated populations, as expected.
‘But, taken with the promising results from other studies in South Africa, vaccines may continue to ease the toll on healthcare systems by preventing severe disease.’
On Saturday, AstraZeneca said its vaccine provided good protection against the variant first discovered in Kent, which is now dominant in the UK. Early results suggest the Pfizer/BioNTech vaccine protects against the new variants.
Early results from Moderna suggest its vaccine is still effective against the South Africa variant.
Meanwhile, a booster jab that will help tackle the South African variant of coronavirus should be ready by the autumn, scientists said yesterday.
Professor Sarah Gilbert, lead researcher in the Oxford team, said current vaccines ‘have a reduction in efficacy against some of the variant viruses’.
But she added: ‘What that is looking like is that we may not be reducing the total number of cases but there’s still protection in that case against deaths, hospitalisations and severe disease.
‘That’s really important for healthcare systems, even if we are having mild and asymptomatic infections, to prevent people going into hospital with Covid would have a major effect.’
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