The Delta strain, first detected in India earlier this year, now accounts for the majority of coronavirus cases across the world.

However, last month a highly mutated version of Omicron in the Republic of South Africa (PAR) prompted countries around the world to impose travel restrictions on South African countries and renew domestic restrictions to slow the spread of the virus.

The WHO said that as of December 9, Omicron had spread to 63 countries. Rapid stress diffusion has been observed in the south, where delta stress is less common, and in the United Kingdom, where delta stress is the dominant form.

However, the organization stressed that the paucity of data means that it is not possible to determine whether the omicron spreads faster because the variant is better able to evade an immune response or because it is more contagious, possibly a combination of the two.

“Preliminary data suggest that Omicron reduces the effectiveness of the vaccine’s protection against coronavirus infection and its transmission,” the WHO said in a statement.

“Based on the data collected so far, Omicron may bypass the Delta strain in cases where the source of infection is unknown,” the organization said.

omicron The alternative has so far caused a “mild” form of the disease or asymptomatic cases, but according to the WHO, the data are not yet sufficient to provide a clinical picture.

PAR had informed WHO about Omicron on 24 November.

Coronavirus vaccine developers Pfizer and BioNTech said last week that three doses of their vaccine provide effective protection against the Omicron variant.

Countries with adequate vaccines, such as Britain and France, have urged their populations to receive a third, booster dose of the vaccine.