The overall global risk related to the new Omicron variant "is assessed as very high," according to a World Health Organization (WHO) technical brief released Monday.

Depending on how transmissible the variant is and whether it could escape immunity, “the likelihood of potential further spread of Omicron at the global level is high,” the WHO brief said.

Depending on these characteristics, there could be future surges of Covid-19, which could have severe consequences.”

The WHO expects data from ongoing further research to be available in the coming weeks.

“Further research is needed to better understand the escape potential against vaccine- and infection-induced immunity,” the WHO said in the brief. “Despite uncertainties, it is reasonable to assume that currently available vaccines offer some protection against severe disease and death.”

The WHO urged member states to accelerate Covid-19 vaccination efforts among eligible populations, as well as “use a risk-based approach to adjust international travel measures in a timely manner.”

Several European countries have now found Omicron cases

A number of European countries have reported their first cases of the Omicron Covid-19 variant, as governments in the region race to understand the scale of its spread.

The UK has identified nine cases so far, with six of those reported in Scotland on Monday.

The Netherlands and Portugal have each discovered 13 infections — with all of Portugal's cases being found among one Lisbon-based football team. The 13 Dutch cases were found after passengers arriving from South Africa were tested at Amsterdam's Schiphol airport on Friday.

Germany has found three cases, while Italy, the Czech Republic and Belgium each have at least one. On Monday, Austria joined the list of nations declaring its first identified case.

The true number of Omicron cases across the continent is likely to be far higher, with sequencing being undertaken to identify which new infections have been caused by the new strain.