Pfizer’s vaccine will work against the South African coronavirus variant — although its mutations could still mean thousands of injected people are vulnerable, a study has suggested.
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.
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, the study found.
But they did not work as well as they would on older versions of the virus because the antibodies were less perfectly matched to the spike proteins on the outside of the bug, meaning they more often failed to stop them.
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. It has sparked fresh fears of lockdowns being extended.
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 may 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 both 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
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.
PFIZER SAYS ITS VACCINE WILL WORK ON SOUTH AFRICA VARIANT
Even with the slight reduction in efficacy, the research strongly suggests the vaccine will still be able to kill off the new strain before it can cause serious illness.
Researchers from Pfizer and the University of Texas took blood samples from vaccinated patients and exposed them to an engineered virus with the worrying mutations found on the South African variant.
They found there was about a noticeable reduction in the production of antibodies, which are virus-fighting proteins made in the blood after vaccination or natural infection.
The study said it found only ‘small effects of these mutations on neutralization… by two [Pfizer] doses.’
In a boost to the world’s immunisation efforts, the team said the number of antibodies produced was still high enough to kill the mutant strain.
This is possible because the immune system generally makes so many antibodies that it creates enough to hit the threshold needed to neutralise – or kill – the virus, and then many more on top, which are expendable.
While the Pfizer results are promising, they are limited because the study did not look at the full set of mutations found in the new South African variant.
The research, first released on a pre-print website in January, was published today in the journal Nature Medicine.
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.
Antibodies are only one type of the immune response to the virus but are the one that vaccine-makers have focused on. Other aspects, such as white blood cells, may also be acting against the virus but not be getting measured.
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, although it could usually still destroy that version of the virus.
They could not give a percentage effectiveness because the trial wasn’t done on people.
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
SAGE adviser warns UK’s lockdown could last even LONGER if South African Covid variant continues to spread
Britain could face further lockdown restrictions if the South African Covid variant becomes more widespread, a SAGE scientist warned today.
A study on Sunday found the Oxford University jab had ‘minimal effect’ in preventing mild disease caused by the strain, suggesting vaccinated people may still be able to catch and spread it.
Professor Mike Tildesley, an infectious disease expert at Warwick University and member of SAGE, said the finding 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 can’t get on top of this.’
Despite the concerning new finding, UK ministers have urged Brits to keep faith in the British-made vaccine, saying there is ‘no evidence’ it will not block severe disease.
Health minister Edward Argar told the public not to lose sight of the main purpose of Covid jabs – 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.
Government sources insisted had not changed the plan to get schools back from March 8. However, they pointed out Boris Johnson had cited the threat of new variants as a factor that will be taken into account when decisions are made on easing lockdown.
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.’
WILL THE CURRENT VACCINES WORK AGAINST SOUTH AFRICAN COVID VARIANT?
The South African variant of coronavirus, known as B.1.351, has mutations on its outer spike proteins that change the shape of the virus in a way that makes it look different to the body than older versions of the virus.
Because the immune system’s antibodies are so specific, any change in the part of the virus that they attach to – in this case the spikes – can affect how well they can do so.
Current vaccines have been developed using versions of the virus from a year ago, which didn’t have the mutations the South African variant does, so scientists are worried the immunity they create won’t be good enough to stop it.
Here’s what we know about the vaccines and the variant so far:
Oxford/AstraZeneca (Approved; Being used in the UK)
Research published in February claimed that the Oxford/AstraZeneca vaccine appears to have a ‘minimal effect’ against the South African variant.
A study of 2,000 people by the University of Witwatersrand in Johannesburg found that two doses of the jab may only offer 10-20 per cent protection against mild or moderate Covid-19.
Nobody in the test group developed severe Covid-19 but the researchers said this ‘could not be assessed in this study as the target population were at such low risk’. Participants’ average age was 31 and they were otherwise healthy.
Scientists working on the vaccine said they still believe it will be protective.
Oxford and AstraZeneca said they are already working on a booster jab targeted at the South African variant and that it will be ready by autumn.
Pfizer/BioNTech (Approved; Being used in the UK)
Two studies suggest that Pfizer and BioNTech’s vaccine will protect against the South African variant, although its ability to neutralise the virus is lower.
One by Pfizer itself and the University of Texas found that the mutations had ‘small effects’ on its efficacy. In a lab study on the blood of 20 vaccine recipients they found a reduction in the numbers of working antibodies to tackle the variant, but it was still enough to destroy the virus, they said.
Another study by New York University has made the same finding on 10 blood samples from people who had the jab. That team said there was a ‘partial resistance’ from the variant and that a booster should be made, but that it would still be more effective than past infection with another variant.
Pfizer is developing an updated version of its jab to tackle the variant.
Moderna (Approved; Delivery expected in March)
Moderna said its vaccine ‘retains neutralizing activity’ in the face of the South African variant.
In a release in January the company said it had tested the jab on the blood of eight people who had received it and found that antibody levels were significantly lower when it was exposed to the South Africa variant, but it still worked.
It said: ‘A six-fold reduction in neutralizing [antibodies] was observed with the B.1.351 variant relative to prior variants. Despite this reduction, neutralizing levels with B.1.351 remain above levels that are expected to be protective.’
Moderna is working on a booster jab to tackle the South African variant.
Janssen/Johnson & Johnson (Awaiting approval; 30m doses)
Janssen, a subsidiary of Johnson & Johnson, has trialled its vaccine in South Africa and found it prevented 57 per cent of Covid cases.
This was the lowest efficacy the company saw in its global trials – in Latin America it was 66 per cent and in the US 72 per cent. These differences are likely in part due to the variants in circulation.
The vaccine was 85 per cent effective at stopping severe disease and 100 per cent effective at stopping death from Covid-19, even in South Africa where the variant is dominant, Janssen said.