Moderna insists its Covid vaccine DOES work on new coronavirus variants

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Moderna’s coronavirus vaccine is effective at protecting against the Kent variant but doesn’t work as well against the strain that emerged in South Africa, the company said today.

In a huge boost to Britain’s vaccination programme, the US firm said laboratory tests found the variant found in the UK had ‘no significant impact’ on the jab.

Britain has ordered 17 million doses of the Moderna jab, which was 95 per cent effective at blocking the original Covid strain. They are due to arrive in spring. 

The researchers took blood samples from patients who had received the vaccine and exposed them to the various mutated strains of the virus.

They found the jab produced six times fewer antibodies – substances made in the blood to fight infections – against the South African variant.

Despite the six-fold reduction, the vaccine produced a high enough level of antibodies to kill the mutant strain, Moderna claimed.   

The findings all but confirm the South African variant does reduce the potency of vaccines and raises the prospect that some people given the jab could still catch the virus.

Moderna said it is now developing a booster jab, to be taken after the original two-dose vaccine, to provide extra protection against the South African variant.   

So far 77 cases of the South African variant have been spotted in the UK, although this number is likely to be far higher because Public Health England only analyses one in 10 random positive swabs.

Reacting to the findings, Professor Jonathan Ball, a molecular virologist at the University of Nottingham, said: ‘The finding that sera raised following Moderna vaccination was significantly reduced against the South African variant suggests that this variant might have arisen following immune selection in individuals previously infected with SARS-CoV-2 coronavirus. 

‘This highlights the real potential for antibody escape variants to arise in the face of sub-optimal immunity.

‘Whilst the vaccine immune sera showed reduced activity it was still able to kill the South African variant virus. We also think that the vaccine is able to generate killer T cells and we hope that these too will still be effective against the variant virus.

‘But this data does show that virus evolution can impact on antibody killing, so it will be important to continue to monitor variant emergence and test whether or not genetic changes might impact on key behaviours like antibody sensitivity, transmission and disease severity.

‘Importantly the variant that has spread widely throughout the UK was fully susceptible to the Moderna vaccine-induced antibodies. It will also be important to see how immunity raised by the AZ and Pfizer vaccines might be impacted by virus mutation.’ 

Professor Paul Hunter, an epidemiologist at the University of East Anglia, said the results were ‘not surprising’ to him.

He added: ‘The key mutation in the English variant (B.1.1.7) is N501Y is not thought to be an escape mutation and so it is unlikely that it would have any effect on vaccine efficacy. 

‘The South African variant (B.1.351) has the N501Y mutation as well but also the E484K mutation which is thought to be an escape mutation and so one would expect some reduced efficacy and this is what has been seen today. Given that the Brazilian variants both contain the E484K mutation it is likely that efficacy to these variants will also be reduced.

‘However, this does not mean that existing vaccines will not still be highly effective. 

‘Long established human coronaviruses also seem to accumulate mutations over time that ultimately lead to these viruses escaping from the immune protection generated by their ancestors. 

‘But each single mutation is unlikely to be sufficient in itself. So we are likely to see gradual accumulation of variants that are more and more able to escape vaccine induced immunity and indeed naturally induced immunity. 

‘But this is to be expected and should not pose unsurmountable difficulties for control of the epidemic.’

Stéphane Bancel, chief executive officer of Moderna, said: ‘As we seek to defeat the Covid-19 virus, which has created a worldwide pandemic, we believe it is imperative to be proactive as the virus evolves.

‘We are encouraged by these new data, which reinforce our confidence that the Moderna Covid-19 vaccine should be protective against these newly-detected variants.

‘Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective to boost titers [antibodies] against this and potentially future variants.’ 

News that the vaccine works against the Kent variant will be a huge boost to Britain’s immunisation efforts.

It means all three of the UK’s main jabs – including Oxford University/Astrazeneca’s and Pfizer/BioNTech’s – are shown to be just as effective on the mutant strain.

The Kent variant was first picked up in the South East in late September and quickly went on to become the dominant strain in the UK, sparking a winter wave of infections and hospital admissions that plunged England into its third national lockdown. 

UK studies have shown the variant is between 50 and 70 per cent more infectious than the original strain. 

A mutation on the variant’s spike protein called N501Y — which protrudes from the coronavirus and hijacks human cells — is thought to make it better at infecting people. 

But the good news is that it doesn’t appear to have changed the virus so much that immune cells triggered by vaccines based on a version of the virus from last year don’t recognise it.

The other major vaccine developers said they were keeping a close eye on the virus’s mutation and laying the groundwork for new jabs in case they are needed in future.

For Pfizer and Moderna, which produce theirs using genetic code called mRNA, it could be as basic as changing the genetic code on a computer and regenerating all of the RNA samples.

For Oxford and Janssen, however, which attach part of the real coronavirus to a living cold virus from a chimp, the companies must go through the process of growing all of these natural components, which slows down development. It takes Oxford around three months to make a batch.

AstraZeneca’s executive vice-president, Sir Mene Pangalos, pointed to this as a reason behind delays to Britain’s vaccine supply in a meeting with MPs last week.

He said: ‘You have to grow cells, and cells divide at a certain speed – you can’t do any faster than the speed at which the cells divide.’

AstraZeneca, which produces a vaccine designed by the University of Oxford, said it is already starting work on designing new vaccines behind the scenes.

A spokesperson for the company said: ‘The University of Oxford and labs across the world are carefully assessing the impact of new variants on vaccine effectiveness, and starting the processes needed for rapid development of adjusted Covid-19 vaccines if these should be necessary.’

Pfizer is also understood to be working on understanding the new variants and how it could adapt its vaccine to tackle them.