-- According to data published on Thursday by the European Centre for Disease Prevention and Control (ECDC), the 50th week of 2021 witnessed 2,644,836 more cases and 26,179 new deaths registered in Europe.

-- For many Europeans and Americans, a surge in COVID-19 infections driven by the highly infectious Omicron variant has thrown a wrench into their holiday season plans, as they are still painfully processing the fact that they have to cancel flights, hotels and other holiday bookings.

-- Surging cases and deaths have already prompted some European countries to consider tightening control measures.

For most Europeans and Americans, the annual Christmas season is a festive period for happy family reunion and joyous holiday travel. But they could not find much to have a good laugh about together this year, as the highly transmissible Omicron variant has triggered another explosion of infections and deaths in their homelands.

While many in the Western society are mournfully changing their holiday plans after airlines and railways cancelled more services at the last minute, experts worldwide are urging rapid re-imposition and upgrade of control measures, as well as broader vaccination efforts, to slow down the spread of the virus and keep the COVID-19-related burden manageable.

SURGING INFECTIONS

According to data published on Thursday by the European Centre for Disease Prevention and Control (ECDC), the 50th week of 2021 witnessed 2,644,836 more cases and 26,179 new deaths registered in Europe.

The 14-day notification rate of reported cases per 100,000 population in Europe has hit roughly 629.2, the ECDC data showed.

France, one of the worst-hit European countries by Omicron, reported on Saturday 104,611 new cases, the highest daily record since the pandemic broke out in the country, bringing its cumulative caseload to 9,088,371, said the French Public Health Agency.

People walk near a fast COVID-19 testing tent near the Arc de Triomphe in Paris, France, Dec. 23, 2021. (Xinhua/Gao Jing)

Local media reported around 20 percent of the new cases in France are related to Omicron.

Official figures released Friday showed that Britain had reported another 122,186 cases in the latest 24-hour period, breaking the record of 120,000 daily cases for the first time since the start of the pandemic. It also reported a further 137 coronavirus-related deaths.

The country had altogether registered some 700,000 cases and 810 deaths in the week ending Friday, up by 48.2 percent and 2 percent respectively from the previous week.

Also on Friday, Spain reported 72,912 new cases, a record high for the third day running. Italy reported 44,595 infections on Thursday, the highest daily count it has ever registered.

Also dire is the situation in the United States. Data from the U.S. Department of Health and Human Services showed that more than 69,000 Americans were hospitalized with COVID-19 on Christmas Eve.

According to the U.S. Centers for Disease Control and Prevention (CDC), nearly 300,000 new cases were reported on Dec. 21, a new high since Jan. 8. About 2,200 new deaths were reported on Dec. 22, the highest single-day increase since Oct. 8.

The CDC has announced that Omicron is the cause of 73 percent of new infections across the United States, and even of 90 percent in some parts of the country.

TRAVEL CHAOS

For many Europeans and Americans, a surge in COVID-19 infections driven by the highly infectious Omicron variant has thrown a wrench into their holiday season plans, as they are still painfully processing the fact that they have to cancel flights, hotels and other holiday bookings.

FlightAware, a flight tracker website, noted that 46 flights from British Airways were canceled on Monday alone. According to media reports, German airline Lufthansa announced that it will cancel 10 percent of its winter flight schedule amid the pandemic. Railway authorities in the Netherlands and Belgium have both decided to cancel daily trains because of rising staff illness or quarantine.

A passenger wearing a face mask is seen in a plane at Ronald Reagan Washington National Airport in Arlington, Virginia, the United States, Dec. 4, 2021. (Photo by Aaron Schwartz/Xinhua)

Besides, FlightAware also noted that a total of 1,033 Monday flights within, into and out of the United States were canceled and 2,982 faced delays due to crew shortages and disrupted operations. A combined 1,700 flights had been canceled on Christmas Eve and Christmas Day.

"The cancellations come at the busiest time of year for air travel," and major U.S. travel hubs were "among the hardest hit," ABC News reported.

Meanwhile, experts and officials are warning the conditions could be even worse in the future. In its weekly epidemiological update published Monday, the ECDC said an increasing number of infections have been reported within Europe, including as parts of clusters and outbreaks, indicating possible community spread.

The spread of Omicron "is extremely rapid, especially among the 20-29 years olds," noted Arnaud Fontanet, an epidemiologist and member of the French Scientific Council. "In January, we are expecting hundreds of thousands of new cases a day."

Given the rising cases in Britain, experts said there are likely to be hundreds of thousands of infections per day, with many being missed by the system.

As Germany is also bracing for a new wave of the pandemic, Ute Teichert, chairwoman of the Federal Association of Public Health Service Doctors, said a large proportion of public health departments in Germany already stopped contact tracing for people infected with COVID-19 due to overload.

"Because of the Omicron variant, we are running into a situation in Germany where health departments will eventually not be able to compensate for sick staff," she said.

Silvio Brusaferro, president of Italy's National Health Institute, has also noted in a statement "the great rapidity of the variant spread, which seems to produce large outbreaks in a short time, and it is expected to become predominate, as it is already occurring in several other European countries."

A COVID-19 notice board is seen at Galleria Alberto Sordi in Rome, Italy, Dec. 24, 2021. (Xinhua/Jin Mamengni)

In the United States, health officials have been warning that Omicron threatens to overwhelm hospitals and healthcare workers. Many hospitals are already overburdened, especially with patients who remain unvaccinated and those who have delayed necessary care during the pandemic. The surging infections and deaths have also created COVID-19 testing shortages.

"Every day it goes up and up. The last weekly average was about 150,000 and it likely will go much higher," Anthony Fauci, U.S. President Joe Biden's chief medical advisor, was quoted as saying by ABC News on Sunday.

TOUGHER RESTRICTIONS

Surging cases and deaths have already prompted some European countries to consider tightening control measures.

In a video posted on social media by Downing Street, British Prime Minister Boris Johnson urged caution and suggested people should take a test before meeting elderly relatives.

The country's Secretary of State for Health and Social Care Sajid Javid reiterated his call for citizens to get vaccinated, tweeting, "If you're eligible for the jab, please come forward as soon as possible."

Germany has added Britain, Denmark, Norway and France to its list of "areas at particularly high risk of infection." Travelers entering Germany from risk areas must quarantine for 14 days, including those who are vaccinated or who recovered from the virus, said the country's Robert Koch Institute for infectious diseases.

The Netherlands has reintroduced a full lockdown, which will remain in force until Jan. 14. Dutch Prime Minister Mark Rutte said at a press conference that "Omicron is spreading even faster than we feared, so we must intervene now."

According to media reports, Spain, Greece and Italy have also reintroduced outdoor mask mandate amid the Omicron surge.

Meanwhile, the United States has shortened the isolation period for healthcare workers infected with COVID-19, due to hospital staff shortages. The CDC said in a new guidance that those workers who had received all recommended vaccine doses, including boosters, do not need to quarantine at home following high-risk exposures.

People wait in line for COVID-19 tests at a mobile testing site on Times Square in New York, the United States, Dec. 20, 2021. (Xinhua/Wang Ying)

The new guidance was immediately condemned by the New York State Nurses Association, which called the CDC's decision "inconsistent with proven science."

"It makes no sense not to take every measure which would reduce risk of healthcare worker infection," it said in a statement.

Amid busy marketing authorization of various vaccines and urgent call worldwide for promoting vaccination, the World Health Organization stressed that "vaccines can offer protection but it is also essential to wear a mask and avoid large crowds to keep COVID-19 away during the holiday season."

"It is not yet known how easily Omicron spreads, how serious symptoms are or how it affects protection from vaccines," it tweeted Monday, adding that to protect oneself and others, it is also necessary to open windows and clean hands.