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.
The South African strain — called B.1.351 — has key mutations on its spike protein which make scientists fear might make it hard for the immune system to recognise
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.’
Up to HALF of people who’ve already had Covid ‘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.
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.
What variants are causing panic around the world?
Real name: B.1.1.7
When was it discovered? The variant was first found in the South East of England and can be traced back to September 2020.
What mutations does it have? It has 23 mutations, some of which change the shape of the spike protein on its outside. The main mutation is known as N501Y. This appears to make it better able to stick to the cells inside the body and makes it more likely to cause infection and faster to spread.
Why is it causing worry? UK studies have shown it is between 50 and 70 per cent more infectious than the regular strain, which has made it harder to control. Preliminary studies also show it is about 30 per cent more deadly than previous versions.
How many people have caught it in the UK? It is the dominant strain in Britain and accounts for the majority of new cases.
Real name: P.1
When was it discovered? In Tokyo, Japan, in four travellers arriving from Manaus, Brazil, on January 2.
What mutations does it have? P.1 has 17 mutations, three of which are particularly concerning to scientists.
Like the Kent variant, it also has the N501Y mutation which suggests it’s more infectious and possibly more lethal.
It also has a spike alteration named E484K, which scientists believe may be associated with an ability to evade parts of the immune system called antibodies.
Researchers suspect this is the case because strains with this mutation have been shown to reinfect people who caught and beat older versions of Covid.
Another key mutation in the variant, named K417T, has the potential to ‘possibly escape some antibodies’, according to British experts.
This mutation is less well-studied and the ramifications of this are still being researched.
Why is it causing worry? There have been a number of proven cases of people catching this variant after beating older versions of the virus. It strongly suggests the variant can evade natural immunity and possibly even vaccines.
How many people have caught it in the UK? It’s not. Public health officials and scientists randomly sample around 1 in 10 coronavirus cases in the UK and they have not yet reported any cases of the variant, but this doesn’t rule it out completely.
South African variant
Real name: B.1.351
When was it discovered? Nelson Mandela Bay, in South Africa’s Eastern Cape Province, in mid-December.
What mutations does it have? The South African variant carries 21 mutations, including E484K and N501Y.
Why is it causing worry? Those two mutations suggest it is more infectious than the older version of Covid and raise the possibility of antibody resistance. However, Sir Patrick Vallance has said there is no reason the South African or Brazilian strains would become dominant in the UK, because they don’t have any evolutionary edge over the Kent strain currently plaguing the country, which is just as transmissible.
How many people have caught it in the UK? At least 77 Brits have been infected with this variant, though the number is likely to be far higher because PHE is only testing random positive samples.