The strain (also known as B.1.1.7 lineage or VOC 202012/01) carries a larger than usual number of genetic changes with 10 mutations on the spike protein. A previous in vitro study investigating one of these more important mutations, N501Y, showed ‘efficient neutralization of the N501Y mutated spike bearing virus’ in vaccinated individuals (the N501Y mutation is also shared with the South African strain).
The new data now encompasses the full set of UK strain spike mutations. The in vitro study has been published today on preprint server bioRxiv and submitted to a peer-reviewed journal. It investigates the capability of sera from vaccinated individuals to neutralize the UK strain: represented by a pseudovirus in the study.
“The preserved neutralization of the pseudovirus bearing the U.K. strain spike by BNT162b2-immune sera makes it likely that COVID-19 caused by the UK virus variant will also be prevented by immunization with BNT162b2," says BioNTech.
“Pfizer and BioNTech are encouraged by these early in vitro study findings.”
The companies note that further research will be required: noting they have not yet established at what point mutations would require a vaccine strain change. But they reiterate that the flexibility of BioNTech’s mRNA vaccine platform would be ‘well suited’ to carry out such adjustments (BioNTech’s CEO has previously suggested a new vaccine could be developed within six weeks).
Researchers generated pseudoviruses bearing the Wuhan reference strain or lineage B.1.1.7 spike protein. Sera of 16 participants was tested for neutralization of both pseudoviruses. There was ‘no biologically significant difference in neutralization activity against the two pseudoviruses’, says the study.
‘The preserved neutralization of pseudoviruses bearing the B.1.1.7 spike by BNT162b2-immune sera makes it very unlikely that the UK variant viruses will escape BNT162b2-mediated protection,’ says the study.
While it notes that a potential limitation of the study may be the use of non-replicating pseudoviruses, it says previous reports have shown good concordance between that and SARS-CoV-2.