That’s the forecast issued Tuesday by experts at the World Health Organization, as the Omicron variant continues to rage across the region, even as the Delta variant is still going strong.

In the first week of 2022, Western Europe saw over 7 million infections. Dr. Hans Kluge, the WHO’s regional director for Europe, said a West-to-East “tidal wave” of infections is on its way. Right now, 1% of the population is catching COVID-19 per week in 26 countries.

“At this rate…more than 50% of the population in the region will be infected with Omicron in the next six to eight weeks,” he said.

Kluge expressed particular concern about the coming wave in central and eastern Europe, where fewer people have been vaccinated, noting that the number of severe cases was likely to increase, overwhelming health care facilities in the area.

Cases in Denmark, he said, have “exploded in recent weeks,” with non-vaccinated patients being hospitalized at six times the rate of vaccinated ones over Christmas week.

In the U.S., the Omicron variant accounted for just 8% of cases one month ago. By Jan. 1, 2022, however, it made up more than 95% of the diagnosed cases in America, according to the CDC. On Monday, the number of COVID-19 hospitalizations in the United States reached a record high, with 132,646 people hospitalized.

While Omicron is potentially less severe, health officials warn the cascade of infections is impacting U.S. hospitals as well, with some suspending elective procedures and some shutting down their maternity wards.