As part of an updated tracking system for SARS-CoV-2 variants, the World Health Organization will move to evaluate omicron sublineages independently to better identify potential new threats.
Prior to the tracking system update, the global agency had classified all omicron subvariants under the umbrella of the omicron variant of concern. As of March 15, it will consider its sublineages independently as either variants under monitoring, VOCs or variants of interest. The definitions for VOC and VOI have also been updated, with VOCs covering only the major virus evolutionary steps. Moving forward, only VOCs will be assigned a Greek letter label.
Since February, viruses in the omicron family have accounted for over 98 percent of publicly available sequences, according to the WHO. Given this, new variants would likely emerge from omicron, "although the emergence of variants derived from previously circulating variants of concern or of completely new variants remains possible."
The changes were made "in order to better identify additional or new threats over and above those posed by the current Omicron viruses in circulation."