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The Covid-19 vaccine developed by BioNTech and Pfizer is likely to be effective against a rapidly spreading strain of the virus that was first discovered in the UK, a laboratory study of the companies has shown.
The variant, known as B.1.1.7, has a large number of mutations, raising concerns that it could bypass the immune defenses created by vaccines being rolled out around the world, a large proportion of which have been manufactured by BioNTech and Pfizer. .
However, researchers at BioNTech headquarters in Mainz found that a test-tube version of the virus that carried all the mutations of the new strain was neutralized by antibodies in the blood of 16 patients who had received the vaccine in previous trials, half of whom were over 55 years old. old.
In a document that has not yet been peer-reviewed, the companies said there was “no biologically significant difference in neutralization activity” between laboratory test results on surrogate versions of the original coronavirus strain, sequenced in China. last january. and the new variant.
But the authors cautioned that “the ongoing evolution of Sars-Cov-2 required continuous monitoring of the importance of the changes to maintain the protection of currently licensed vaccines.”
The test is the first of its kind to be completed by a major vaccine manufacturer, as companies are quick to verify their hits against the new variant.
Pfizer and researchers at the University of Texas had already compared it to one of the most troubling changes in the new variant that emerged in the UK and South Africa, in a laboratory study published earlier this month.
Moderna and Oxford / AstraZeneca, which are in the process of testing their vaccines, have previously said they hoped their hits would protect against B.1.1.7.
But a group of scientists in South Africa warned that vaccines could be less effective against the 501Y.V2 strain that is driving a second wave of Covid-19 infections there, because it has an extra mutation in a key part of the spike protein that the virus uses to enter human cells.
A study of serum from 44 South Africans, who had previously been infected with older versions of the Sars CoV-2 virus, found that 90 percent were not fully protected against the new variant, and antibodies in about half of the sample were absent. in all protector.
Salim Abdool Karim, the South African government’s senior adviser on Covid-19, said: “The antibodies in vaccines are different and may or may not be affected. We do not yet have empirical evidence on whether vaccines are effective against the 501Y.V2 variant. Studies are underway. “
Even if vaccines still work well against current variants, vaccine manufacturers and regulators are beginning to prepare for the virus to keep mutating.
If vaccines become significantly less effective, companies will have to adapt their formulations and manufacture new batches. The BioNTech researchers said that, unlike long-standing flu vaccines, the point at which the vaccine would have to be adjusted to combat any new strains “has not been established for Covid-19 vaccines.”
Previously, BioNTech has said that it could modify its vaccine to deal with a new strain in about six weeks. But it will be up to regulators to decide what evidence they will need to be satisfied that a modified product is safe and effective, and whether they will need further clinical trials.
