MOSCOW, October 25. /TASS/. The Delta strain accounts for nearly 100% of coronavirus cases worldwide, Anna Popova, chief of Russia’s sanitary watchdog, said on Monday.

"We observe sublines within Delta, which now accounts for 100% of cases worldwide. Not long ago, it was 95% and now it is nearing 100% The strain has become dominant and is spreading across the world," she said in an interview with Russia’s TV Channel One.

According to Popova, the speed of the Delta strain mutation is by six times slower than that of flu and by 21 time slower than that of HIV. But it mutates twice as quick as the measles virus and 200 times as quick as the smallpox virus.