Two days after a new variant of COVID-19 was identified in South Africa, the World Health Organization (WHO) has given a label to the strain.

On Friday (Nov. 26), WHO announced that the new strain, which was previously labeled lineage B.1.1.529, is now to be called omicron. They are also calling it a “variant of concern” rather than a “variant of interest” due to its amount of mutations, among other things.

“This variant has a large number of mutations, some of which are concerning,” reads one part of WHO’s press release. “Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other VOCs. The number of cases of this variant appears to be increasing in almost all provinces in South Africa. Current SARS-CoV-2 PCR diagnostics continue to detect this variant. Several labs have indicated that for one widely used PCR test, one of the three target genes is not detected (called S gene dropout or S gene target failure) and this test can therefore be used as marker for this variant, pending sequencing confirmation. Using this approach, this variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage.”

In a video WHO posted to Twitter, Maria Van Kerkhove, who operates as the organization’s technical lead on COVID-19, spoke on the measures being taken to deal with the strain.

“There’s a lot of work that is ongoing in South Africa and in other countries to better characterize the variant itself in terms of transmissibility, in terms of severity and any impact on our countermeasures, like the use of diagnostics, therapeutics or vaccines,” she said. “So far there’s little information, but those studies are underway.”

Watch Kerkhove speak on omicron for yourself in the video below.