Countries should consider bringing back Work From Home and masks to fight the “Kraken” sub-variant, EU health experts have said, despite admitting it is low risk to the general population and there is no evidence it is more severe.

On Thursday, the European Centre for Disease Prevention and Control issued a threat assessment brief for Omicron XBB.1.5, which first emerged in the US in October.

The report states that the new variant is spreading 12 per cent faster than other circulating strains, and is likely to become dominant in Europe in the next one to two months. The WHO has warned that XBB.1.5 is the most transmissible sub-variant detected to date.

However, the EDCD report said that vaccines still appeared to be effective, adding that there is currently no indication that it is more severe even though increased spread would lead to a larger number of severe cases.

The experts assessed the risk to the general population as “low”, but said the variant was a “moderate to high” threat to the elderly and immunocompromised or those who had not been vaccinated.

The Omicron sub-lineage has been unofficially nicknamed the “Kraken” because of its potential to reignite the pandemic.

In mythology, the Kraken was a sea creature that emerged from the deep to attack sailing ships.

Earlier this week the UK Health and Security Agency released its own variant technical briefing on XBB.1.5 showing that the sub-variant is currently at very low prevalence in Britain, with experts uncertain if it is growing.

The risk assessment suggested it does have a growth advantage over the current dominant BQ.1 Omicron variant, and may spread almost 40 per cent faster. But cases are so low that the sub-lineage has not yet been designated a variant of concern by the UKHSA.