Russia detects 'more contagious' subvariant of COVID-19 Omicron strain, know all about it

Russia has detected a "more contagious" subvariant of the COVID-19 Omicron strain, confirmed a senior official at the national consumer health watchdog Rospotrebnadzor. According to the TASS news agency, the BA.4 sub-lineage of the SARS-CoV-2 Omicron variant has been found in the country. Russian scientist Kamil Khafizov stated that it was detected while examining a sample collected last month. "The genome of the BA.4 lineage of the SARS-CoV-2 virus has been deposited into the VGARus base, developed by Rospotrebnadzor’s Central Scientific Research Institute of Epidemiology," TASS News agency quoted Khafizov as saying while speaking to reporters on Sunday. He told the reporters that the samples were collected by the two research institutes in May this year.

"One sample was deposited by the Smorodintsev Research Institute of Influenza, and another one - by Rospotrebnadzor’s Central Scientific Research Institute of Epidemiology," added the Russian Health Watchdog. Further, he said that the country has been reporting maximum cases due to the BA.2 variant and its sub-variants. "BA.2 is responsible for all the new cases registered in the country," he added. According to the Russian scientist, good herd immunity, acquired through vaccination and previous waves of the lethal virus, has prevented the new virus from turning into a fatal situation.

However, he acknowledged that a number of researches published indicate that the BA.4 and BA.5 sub-lineages of omicron are slightly more transmissive than earlier versions of the coronavirus. The same theory was echoed by the head of the World Health Organization last month. WHO chief Tedros Adhanom Ghebreyesus said that Omicron sublineages BA.4 and BA.5 were driving a surge of the infection in unvaccinated nations and added the BA.2 subvariant remains dominant across the world. 

What is Omicron Subvariant BA.4?

According to the European Centre for Disease Prevention and Control, both BA.4 and BA.5 were first detected in South Africa in January and February 2022, respectively, and since then they have become the dominant variants there. Both lineages contain the amino-acid substitutions L452R, F486V, and R493Q in the spike receptor binding domain compared to BA.2. Preliminary studies suggest a significant change in antigenic properties of BA.4 and BA.5 compared to BA.1 and BA.2, especially compared to BA.1. Additionally, there is an increasing trend in the variant proportions for BA.5 observed in Portugal in recent weeks, accompanied by an increase in COVID-19 case numbers and test positivity rate.

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