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Paris (AFP)
As the British coronavirus variant seizes countries’ pandemic plans due to its increased transmissibility, other mutations in the Sars-CoV-2 are causing concern among scientists trying to determine if they will still respond to vaccines.
In particular, one mutation, known as E484K, which was initially detected in South Africa and with subsequent variants in Brazil and Japan, raised alarm among researchers.
Ravi Gupta, professor of microbiology at the University of Cambridge, said it was the mutation – and not the British variant – that was ‘the most worrying of all’.
Although research on the new variant is limited, a Brazilian study this month looked at a patient who had recovered from Covid-19 only to be re-infected with the new, mutated strain.
The paper has yet to be reviewed by the peer, but the authors found that the E484K mutation could be “associated with the escape of neutralizing antibodies,” meaning it could bypass the body’s natural defense memory that confers immunity.
As countries accelerate their vaccination programs, there are concerns that the new mutation may make certain vaccines less effective.
The Pfizer and Modern vaccines, for example, use mRNA technology to instruct the body to produce a harmless coronavirus protein, which then kills the immune system in anticipation of an actual infection.
With E484K, as with the British variant, the mutation takes place on the ear protein of the virus, making it possible to bind more easily to human cell receptors, increasing its contagion.
Gupta said the mutation could be a start to problems with vein vaccinations.
“They all need to be effective at the moment, but we are concerned about further mutations occurring on top of this,” he told AFP.
– ‘Bypass current protection’ –
Pfizer and German partner BioNTech said last week that their vaccine is effective against the N501Y mutation found on the British virus variant known as B117.
Francois Balloux, professor of computer systems biology and director of the Genetics Institute of the University College London, said it was unlikely that the South African variant had mutated sufficiently to ‘circumvent the protection afforded by current vaccines’.
But he warned: ‘The E484K mutation has been shown to reduce antibody recognition.
“As such, it helps the Sars-CoV-2 virus bypass the immune protection provided by previous infection or vaccination,” Balloux said.
The new coronavirus has had several mutations since it appeared in late 2019, and most have had an insignificant effect on its transmissibility or severity.
But the British variant has shown in several studies to be up to 70 per cent more contagious than normal virus strains.
And the South African variant appears to be more effective in avoiding the body’s natural response.
– New vaccines? –
One preliminary study in December concluded that the two new variants show that Sars-CoV-2 ‘has the potential to elicit an effective immune response’.
Researchers have studied what happened to the virus when it was left in contact with plasma taken from a patient recovering from Covid-19.
Within three months, the virus adopted several mutations, including E484K.
The authors suggested that ‘vaccines and antibodies that can control developing variants should be developed.’
Lead researcher Rino Rappuoli, an immunologist at pharmaceutical giant GlaxoSmithKline, told AFP that the current protein mutations in the vein may not be a problem for existing vaccines.
And even if the virus mutates to better avoid the immune response, vaccines should at least provide effective immunity.
“Even if you reduce the effectiveness, the virus will normally be neutralized,” Vincent Enouf, a Pasteur Institute in Paris, told AFP.
To be on the safe side, Gupta called for an accelerated vaccination program, which provides as much immunity as current vaccines can deliver ‘as quickly as possible around the world’.
© 2021 AFP