A more contagious subvariant of the Covid-19 Omicron strain has been detected in Russia, the country’s senior official at the national consumer health watchdog Rospotrebnadzor said. According to the TASS news agency, the BA.4 sub-lineage of the SARS-CoV-2 Omicron variant has been found in Russia.
Russian scientist Kamil Khafizov said, “The genome of the BA.4 lineage of the SARS-CoV-2 virus has been deposited in the VGARus database”. According to Khafizov, those samples were collected in late May.
“At present, the BA.2 variant and its sub-variants are dominant in Russia, accounting for about 95% of all new cases,” he said.
The scientist, citing studies, said BA.4 and BA.5, are a little bit more transmissible than the early forms of Omicron.
He said that the good herd immunity, acquired through vaccination and previous waves of the novel coronavirus, prevents the spread of new omicron sub-variants in Russia at the moment. “However, a number of researches published lately show that the BA.4 and BA.5 sub-lineages of omicron are slightly more transmissive than earlier versions of the omicron,” the scientist added.
The BA.4 variant was first detected from a specimen collected on January 10, 2022 in South Africa. BA.4 shares many of the same mutations as the original Omicron variant, but have more in common with the BA.2 variant. It possesses a number of additional mutations, some of which could change their characteristics. The BA.4 Omicron subvariant carries an L452R mutation, which was also previously detected in the Delta variant, and is thought to make the virus more contagious by enhancing the virus’s ability to attach to human cells; it may also help it to partially evade destruction by immune cells. The subvariant also possesses a genetic change, called an F486V mutation, near where their spike protein binds to human cells. This may also help them partially evade our immune response.
Last month, South African scientists found that the sublineages of the Omicron coronavirus variant can dodge antibodies from earlier infection well enough to trigger a new wave. BA.4 made up 5.4% of the variants in the US as of June 4. In India, states like Tamil Nadu, Maharashtra, Andhra Pradesh, and Telangana have detected BA.4 cases. These variants have not been associated with disease severity or increased hospitalization.
