Variant AY.4.2 is one of 45 subspecies of the delta variant, first identified in the UK back in July and then spreading to the United States, Israel and several European countries. According to Khafizov, AY.4.2 carries two characteristic mutations in the S-protein gene, causing amino acid substitutions Y145H and A222V. The expert believes that the new version may begin to supplant the “original” version of the delta, but there is no reason to believe that this will happen at the same rapid pace.
“It was first seen in July, and since then the proportion of this delta branch has slowly increased. It is potentially just a slightly more infectious strain, ”Kamil Khafizov said.
Professor of the Institute of Genetics at the University of London, Francois Balloux, said that variant AY.4.2 may be 10% more infectious. In the UK, the spread of a new subspecies has led to a small but not critical surge in incidence.
“None of the mutations is a priori an obvious candidate for increasing viral transmissibility, but we learned that mutations can have different, sometimes unexpected, effects in different strains,” the scientist said.
Molecular biologist and science journalist Irina Yakutenko believes that fears about the increased danger of the new version are greatly exaggerated and so far there is no reason to believe that it can seriously change the course of the pandemic, as was the case with the delta and alpha variants.
“For some reason, the spike protein mutations Y145H and A222V attracted the most attention of the press. Such attention to these changes is not very clear, they have repeatedly appeared in other lines of coronavirus, which have since become extinct. Yes, superimposed on those changes that were not in the old versions of SARS-CoV-2, these mutations can give the virus some new properties, but so far those are not visible, ”the scientist wrote on her Facebook page.
The increase in the incidence in the UK may not be associated with the spread of a new variant, but with the abolition of restrictions and a cold snap, due to which people spend more time indoors, suggested Irina Yakutenko.