GENEVA, NOVEMBER 26

The World Health Organization is convening an experts' meeting from Geneva at midday (1100 GMT) on Friday to assess the new COVID-19 variant B.1.1.529 amid growing concern, a spokesperson said.

European and Asian countries tightened travel restrictions on Friday after the new and possibly vaccine-resistant coronavirus variant was detected in South Africa, with the EU, Britain and India among those announcing stricter border controls.

"We don't know very much about this yet. What we do know is that this variant has a large number of mutations. And the concern is when you have so many mutations it can have an impact on how the virus behaves," said Maria van Kerkhove, an epidemiologist and WHO technical lead on COVID-19.

"This is one to watch, I would say we have concern. But I think you would want us to have concern," she told viewers of an event on social media on Thursday.

Van Kerkhove said that it was good that variants were being detected, adding: "It means that we have a system in place."

WHO spokesperson Christian Lindmeier said that the U.N. agency's technical advisory group and other experts on virus evolution were conferring with South African researchers.

"WHO is convening a meeting ... to better understand the timeline for studies that are under way and to determine if this variant should be designated as a variant of interest or variant of concern," he said.

Nearly 100 sequences of the variant have been reported, and early analysis shows it has "a large number of mutations" requiring further study, Lindmeier said.

The WHO had no comment for now on travel restrictions imposed by some authorities on southern African countries linked to the variant, he added.