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."