Russian Health Watchdog Rospotrebnadzor confirmed detection of the more contagious Omicron subvariant BA.4 in Russia.
According to Kamil Khafizov, the head of genome research at Rospotrebnadzor's Central Research Institute for Epidemiology, told reporters that two national labs had submitted the viral genome of the BA.4 sublineage to the VGARus database.
He also mentiomed that the concerned samples dated back to late May.
The scientist also added that the BA.2 subtype still accounted for 95% of all new cases in Russia.
"A number of studies published recently have revealed that variants, known as BA.4 and BA.5, are a little bit more transmissible that the early forms of Omicron," he said.
Previously, the global health watchdog World Health Organization (WHO) had predicted in May that Omicron sublineages BA.4 and BA.5 were driving a surge of the disease in unvaccinated countries while BA.2 subvariant remains dominant in the world.
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.
On May end, four cases of B.A. 4 variant and three cases of B.A. 5 variants of the Omicron sub-lineage of coronavirus were found in Maharashtra. Their samples were taken between May 4 and 18. Two of them had travelled to South Africa and Belgium, while three had travelled to Kerala and Karnataka.
About BA.4 Omicron Subvariant
It has been reported that the BA.4 shares more similarity with the BA.2 variant of Omicron than the original variant. The BA.4 Omicron subvariant carries an L452R mutation, which was also previously detected in the Delta variant. This particular mutation is responsible for making the virus more contagious by enhancing the virus’s ability to attach to human cells. The L452R mutation also plays a pivotal role in evading destruction by immune cells .
Besides, the BA.4 subvariant is also known to possess another mutation called an F486V near the spike protein's binding site to human cells. This may also help them partially evade our immune response, according to studies.