More than half of people in Europe are on track to contract the Omicron coronavirus variant in the next two months if infections continue at current rates, the World Health Organization said Tuesday.

Speaking at a press conference, regional director Hans Kluge warned that the Omicron variant represented a "new west-to-east tidal wave sweeping across" the European region.

"At this rate, the Institute for Health Metrics and Evaluation (IHME) forecasts that more than 50 percent of the population in the region will be infected with Omicron in the next six to eight weeks," Kluge told reporters.

The WHO's European region comprises 53 countries and territories including several in Central Asia, and Kluge noted that 50 of them had confirmed cases of the Omicron variant.

According to the WHO, 26 of those countries reported that over one percent of their populations were "catching Covid-19 each week" as of January 10, and that the region had seen over seven million new virus cases reported in the first week of 2022 alone.

Kluge said the "unprecedented scale of transmission" now meant countries were seeing rising hospitalisations from Covid-19, but added that mortality rates were still stable. 

The wave "is challenging health systems and service delivery in many countries where Omicron has spread at speed, and threatens to overwhelm in many more," Kluge lamented.

Referencing data collected over the last few weeks, Kluge said the variant was confirmed to be more transmissible and "the mutations it has enable it to adhere to human cells more easily, and it can infect even those who have been previously infected or vaccinated."

However, Kluge also stressed that "approved vaccines do continue to provide good protection against severe disease and death, including for Omicron."

Despite reports of a higher degree of asymptomatic cases and lower proportion of hospitalisations for Omicron cases, the WHO said it was too early to treat the disease as endemic -- meaning a regularly occurring milder disease like the flu.

"We still have a virus that's evolving quite quickly and posing quite new challenges. So we're certainly not at the point of being able to call it endemic," WHO senior emergencies officer Catherine Smallwood told reporters.

"This virus, as we know, has surprised us more than once... The prime aspirational goal for 2022 is to stabilise the pandemic," Kluge concluded. 

Worldwide, 5.5 million deaths have been associated with Covid-19, according to a toll compiled by AFP from official sources.

The WHO says the real toll may be two to three times that figure.