MOSCOW, February 17. /TASS/. The Omicron strain of SARS-CoV-2 is replicating in lower respiratory airways ten times slower that the Delta strain, Natalia Pshenichnaya, deputy director of the Central Research Institute of Epidemiology, said on Wednesday.

"Omicron practically doesn’t replicate in lower airways, or, al least replicates much slower than Delta. There is data that it replicates ten times slower," she said.

As for upper airways, Omicron replicates as actively as other coronavirus strains, she added.

On November 26, 2021, the World Health Organization (WHO) designated the B.1.1.529 variant identified in South Africa as a "Variant of Concern" and assigned it the Greek letter omicron. In its statement, the WHO noted that "this variant has a large number of mutations, some of which are concerning." By now, Omicron has been identified in most of the world nations, including Russia, causing an explosive incidence growth. According to the latest statistics, Omicron accounts for 72.5% of coronavirus cases in Russia.