The World Health Organization has named variant B.1.1.529 Covid as Omicron and says an advisory group has recommended that it be designated as "disturbing".
In a statement, the WHO said preliminary evidence suggests the latter variant carries a "higher risk of re-infection than other disturbing variants".
WHO added:
The first known known infection B.1.1.529 was from a specimen collected on November 9, 2021. This variant has a large number of mutations, some of which are troubling. Preliminary evidence suggests an increased risk of reinfection with this variant, compared to other disturbing variants.
The number of cases of this variant seems to be increasing in almost all the provinces in South Africa.
