The WHO has said it is the "most transmissible subvariant that has been detected yet".
A new Covid-19 subvariant, XBB.1.5, has been detected in Ireland, according to the Health Protection Surveillance Centre (HPSC).
Data published by the agency shows that less than five cases of the subvariant, nicknamed "Kraken", were discovered in the country in the four weeks leading up to Christmas.
https://twitter.com/hpscireland/status/1612429242201001985
XBB.1.5 is an Omicron variant and was originally identified in October 2022.
It has since been detected in at least 30 countries, with the World Health Organisation (WHO) describing it as the "most transmissible subvariant that has been detected yet".
In a briefing last week, the WHO's technical lead on Covid-19 Dr Maria Van Kerkhove said that Kraken has mutations that allow the virus to "adhere to the cell and replicate easily".
"This is a sub-lineage of XBB which is a recombinant of two BA.2 sublineages," she explained.
"We are concerned about its growth advantage... It is rapidly replacing other sub-variants in some countries.
"Our concern is how transmissible it is. It does have immune escape like we've seen with XBB.
"But it is one of another sub-variant of Omicron that is in circulation and the more this virus circulates, the more opportunities it will have to change."
https://twitter.com/DrTedros/status/1611275739638403072
While the WHO does expect further waves of infection around the world, Van Kerkhove said this does not have to translate into further waves of death because countermeasures, such as vaccines, continue to work.
She also stated that though the WHO does not have any data on the subvariant's severity yet, it also does "not have an indication that severity has changed with XBB.1.5".
"That is something that is on our radar... That is something that we are watching very closely," the doctor added.
