Scientists on alert over heavily mutated Omicron Covid variant

Johannesburg, Nov 27:  Researchers are racing to track the rise of the new variant of the SARS-CoV-2, which is found to harbour a large number of the mutations found in other variants, including Delta.

The new variant, known as B.1.1.529, has been detected in small numbers in South Africa. The WHO on Friday assigned the Greek letter Omicron to the variant.

Researchers spotted B.1.1.529 in genome-sequencing data from Botswana. The variant stood out because it contains more than 30 changes to the spike protein -- the SARS-CoV-2 protein that recognises host cells and is the main target of the body's immune responses, Nature reported.

Many of the changes have been found in variants such as Delta and Alpha, and are linked to heightened infectivity and the ability to evade infection-blocking antibodies.

"There's a lot we don't understand about this variant," said Richard Lessells, an infectious-diseases physician at the University of KwaZulu-Natal in Durban, South Africa, at a press briefing organized by South Africa's health department on November 25.

"The mutation profile gives us concern, but now we need to do the work to understand the significance of this variant and what it means for the response to the pandemic," he added.

Genome sequencing and other genetic analysis showed that the B.1.1.529 variant was responsible for all 77 of the virus samples they analysed from Gauteng, collected between 12 and 20 November, the report said.

The variant harbours a spike mutation that allows it to be detected by genotyping tests that deliver results much more rapidly than genome sequencing does, Lessells said.

The researchers plan to test the virus's ability to evade infection-blocking antibodie