The new Omicron sub-variant XBB.1.5 is causing some concern in Asia and the US, where it is spreading rapidly.
XBB.1.5 is a sub-lineage of the Omicron subvariant XBB and has been deemed by the World Health Organization (WHO) as the “most transmissible” COVID strain so far.
The subvariant, which has earned the nickname Kraken on social media, is spreading rapidly in Asia and is believed to now account for over forty percent of COVID cases in the US, making it the dominant strain in the country.
At the beginning of December, it accounted for only four percent of cases, so it has quickly overtaken other versions of Omicron.
COVID-19 hospital admissions have been rising in recent weeks across the US. Symptoms of XBB.1.5 are thought to be similar to those of previous Omicron strains, but it’s still too early to confirm this. Most people experience cold-like symptoms.
Omicron subvariant XBB 1.5 has a “growth advantage” above all other
Scientists from WHO confirmed on Wednesday that XBB.1.5 has a “growth advantage” above all other sub-variants seen so far. But they said there was no indication it was more serious or harmful than previous Omicron variants.
Maria Van Kerkhove, COVID-19 technical lead at WHO, said the rate XBB.1.5 spreads at is a “concern.”
“The more this virus circulates, the more chances it will have to change,” she said, adding that further waves of transmission do not necessarily have to translate into more deaths, with the wide availability of vaccination and drugs.
According to Cambridge University’s Professor Ravindra Gupta, a change to Omicron’s spike protein makes XBB.1.5 better suited to escaping antibodies. The change also helps it to cling on to and enter cells.
The WHO said it would keep a close watch on lab studies, hospital data, and infection rates to find out more about its impact on patients.