Omicron Expected to Be Dominant Variant in EU by Mid-January, With 66.6 Percent Vaxxed

European Union officials expect the Omicron variant to become the dominant coronavirus strain by mid-January, but European Commission President Ursula von der Leyen expressed optimism Wednesday in the highly vaccinated region's ability to fight it.

Von der Leyen said the 27-nation EU is facing a double challenge, as new infections are "almost exclusively" caused by the Delta variant and now Omicron is hitting the region. But she also said that with 66.6 percent of the EU's population fully vaccinated, she is confident in the region's "strength" and "means" to overcome new waves.

The European Centre for Disease Prevention and Control says that the 66.6 percent average figure does not account for some of the disparity in EU nations' vaccination rates. While some countries, such as Portugal and Denmark, have fully vaccinated over 82 percent of their residents, others are falling behind, like Bulgaria, with only 26.6 percent fully vaccinated.

Von der Leyen said nations with lower rates need to find ways to fight vaccine hesitancy and skepticism.

"Because the price that we will pay if people are not vaccinated continues to increase," she said. "It's also a problem for our elderly citizens, who once again this Christmas can't see their grandchildren. And it's also a problem for those children who once again can't go to school. What kind of a life is that?"

Continental Europe can look at Britain for a sense of what lies ahead as Omicron spreads, for U.K. officials say it will be the dominant variant there within days. The head of the U.K. Health Security Agency, Dr. Jenny Harries, said Omicron is displaying a staggering growth rate compared with previous variants.

"The difficulty is that the growth of this virus, it has a doubling time which is shortening, i.e., it's doubling faster, growing faster,'' Harries told a parliamentary committee on Wednesday. "In most regions in the U.K., it is now under two days. When it started, we were estimating about four or five.''

Harries said the variant poses "probably the most significant threat we've had since the start of the pandemic."

Alarming rises in infections as winter approaches and the Delta variant remains at large prompted many European governments to implement public health measures as excess mortality increased during the fall.

The head of the World Health Organization says that 77 countries have reported cases of Omicron but that the variant is probably in most countries by now, just not yet detected. The WHO says data is still coming in and much remains unknown about the new variant. According to an analysis Tuesday of data from South Africa, where Omicron is driving a surge in infections, the variant seems to be more easily spread from person to person and is better at evading vaccines, but it's causing milder COVID-19 cases.

"Omicron is spreading at a rate we have not seen with any previous variant. We are concerned that people are dismissing Omicron as mild," WHO Director-General Tedros Adhanom Ghebreyesus said. "Surely we have learned by now that we underestimate this virus at our peril."

He emphasized that vaccines were just one tool—if a major one—to fight the pandemic, along with measures like mask wearing, better ventilation indoors, social distancing and washing hands.

With Omicron now spreading, more countries are adopting restrictions. Italy this week required negative tests from vaccinated visitors, raising concerns that similar moves elsewhere will limit the ability of EU citizens to travel to see friends and relatives over the holidays.

Portugal adopted a similar measure on December 1, requiring a mandatory negative test for all passengers on arriving flights, regardless of their vaccination status, point of origin or nationality.

German Chancellor Olaf Scholz vowed Wednesday that his new government would do everything for Germany to overcome the coronavirus pandemic and let people return to normal lives.

"We have no time to waste," said Scholz, who took office as Germany grapples with its biggest wave of infections during the pandemic to date.

Scholz also said his German government won't tolerate a "tiny minority" of extremists trying to impose their will against coronavirus policies.

As governments braced for the holiday season, Greece, Italy, Spain and Hungary began vaccinating children ages 5 to 11 against the virus.

EU leaders have a summit scheduled for Thursday in Brussels.

The Associated Press contributed to this report.