MOSCOW, November 1. /TASS/. Only isolated cases of the SARS-CoV-2 Lambda and Mu strains have been identified in Russia but monitoring continues, Anna Popova, chief of Russia’s sanitary watchdog, said on Monday.

"There are isolated cases of the Lambda and Mu variants, which are not spreading in Russia. But the situation is under strict control in line with the presidential instruction," she said, adding that the Delta strain accounts for 98% of coronavirus cases in Russia and is nearing 100% worldwide.

Director of the Central Research Institute of Epidemiology Vasily Akimkin said earlier that three cases of the Mu variant and one Lambda case had been confirmed in Russia.