More contagious Omicron subvariant of coronavirus detected in Russia - consumer health watchdog

MOSCOW. June 14 (Interfax) - The more transmissible BA.4 Omicron subvariant has been identified in Russia; first samples with the new Covid-19 strain were sent to laboratories in late May, Kamil Khafizov, head of the research group developing new sequencing-based diagnostic methods at the Central Research Institute of Epidemiology of the Russian consumer health watchdog Rospotrebnadzor said.

"The genome of SARS-CoV-2 virus pertaining to the BA.4 Omicron subvariant has been deposited in the VGARus database, developed by the Central Research Institute of Epidemiology of the Rospotrebnadzor. The first sample has been deposited by the [Russian Health Ministry's] Smorodintsev Research Institute of Influenza, and a second one by the Central Research Institute of Epidemiology of the Rospotrebnadzor. The biological material sampling was dated late May," Khafizov told reporters on Sunday.

Recently published studies have shown that "variants of the virus known as BA.4 and BA.5 are slightly more transmissible than earlier Omicron forms," he said.

Khafizov noted, however, that currently prevailing the BA.2 'Stealth' Omicron variant and its subvariants make up for approximately 95% of all new coronavirus cases in Russia.

"To a large extent, new Omicron subvariants are not spreading too widely thanks to the good heard immunity formed earlier through vaccination and the proportion of those who previously had coronavirus infections, as well as the anti-epidemic measures that were taken," Khafizov said.

In April, virologists at Catholic University of Leuven revealed the first case where the new version of the Omicron coronavirus variant called Ba.4 was detected in Belgium. The BA.4 and BA.5 versions are also present in South Africa, Botswana, Germany, Denmark and Britain, according to the Belgian media.

The BA.4 and BA.5 subvariants spread more easily among people, and it is harder for the human immune system to track them.

With higher levels of contagiousness, these two subvariants, BA.4 and BA.5, have drawn the attention of the World Health Organization.