Flight disruptions in the United States showed few signs of abating on Monday as many people embarked on their first trips in almost two years, and Dr. Anthony S. Fauci, the nation’s top infectious disease expert, raised the possibility of a vaccination requirement for air travel.
At least 2,400 more flights were canceled Monday, including about 900 U.S. flights, as the highly transmissible Omicron variant is sending daily caseloads in parts of the United States soaring to levels higher than last winter’s pandemic peak.
While the cancellations were only a small percentage of overall flights, the problem threatened to extend into the holiday week.
“When you make vaccination a requirement, that’s another incentive to get more people vaccinated,” Dr. Fauci said on MSNBC on Monday. “If you want to do that with domestic flights, I think that’s something that seriously should be considered.”
Over the holiday weekend, airlines canceled thousands of flights as the Omicron variant hit flight crews. In all, about 2,300 U.S. flights were canceled on Saturday and Sunday of the Christmas holiday weekend, with more than 3,500 more grounded globally, according to FlightAware, which provides aviation data. On Sunday alone, more than 1,300 U.S. flights and nearly 1,700 additional ones worldwide were canceled.
While some of the groundings were caused by bad weather and maintenance issues, several airlines acknowledged that the current wave of coronavirus cases, contributed significantly. A JetBlue spokesman said that the airline had “seen an increasing number of sick calls from Omicron.”
Twelve percent of JetBlue flights, 6 percent of Delta Air Lines flights, 5 percent of United Airlines flights and 2 percent of American Airlines flights on Sunday had been canceled, according to FlightAware.
Southwest Airlines canceled 68 flights, or 1 percent, according to FlightAware, because of weather, said Dan Landson, a Southwest spokesman. “We haven’t had any operational issues related to Covid,” he said in an email.
The stock prices of United, Delta, American and Southwest — the four largest U.S. carriers — were less than 1 percent lower on Monday.
Traveling rebounded sharply this year, making the situation at airports worse: Roughly two million people passed through screening checkpoints each day last week, according to the Transportation Security Administration, and on Sunday. The numbers on Christmas Eve and Christmas Day were much higher than last year, and some figures even exceeded those of the same days two years ago, when virtually no Americans were aware of a virus beginning to circulate halfway around the world.
There were hints that the worst of the cancellations may be over in the United States. For instance, Delta had expected to cancel about 200 flights on Sunday, fewer than the 300 it had predicted a day earlier, according to a spokeswoman. It is forecasting only 40 cancellations on Monday.
On the other hand, airlines also expect lots of travel on Jan. 2, a Sunday. And the Omicron variant, which is now responsible for more than 70 percent of the new coronavirus cases in the United States, has already helped push daily case averages in the United States above 200,000 for the first time in nearly 12 months, according to The New York Times’s coronavirus tracker.
An airline trade group has asked the Centers for Disease Control and Prevention to shorten the recommended isolation period for fully vaccinated employees who test positive to a maximum of five days, from 10 days, before they can return with a negative test.
“Swift and safe adjustments by the C.D.C. would alleviate at least some of the staffing pressures and set up airlines to help millions of travelers returning from their holidays,” said Derek Dombrowski, a JetBlue spokesman.
The flight attendants’ union, however, has argued that reductions in recommended isolation times should be decided on “by public health professionals, not airlines.”
Some of this weekend’s delays had little to do with the pandemic. Alaska Airlines had instituted an extensive program to keep crews healthy and even had members of its management team who are trained to be crew members step in, said a spokeswoman, Alexa Rudin.
On Saturday and Sunday, it had only a handful of cancellations related to crew exposures to the coronavirus, according to Ms. Rudin. Yet it had canceled 170 flights those two days, according to FlightAware, including 21 percent of its Sunday flights, because of unusually cold and snowy weather in the Pacific Northwest, which affected its hub, Seattle-Tacoma International Airport.
In New York City, the Metropolitan Transportation Authority, is also dealing with an uptick in positive cases among its staff. But subway service on Monday was running on a normal schedule, with scattered exceptions, Demetrius Crichlow, senior vice president for subways, said.
An Israeli hospital on Monday began a study to test the safety and effectiveness of a fourth dose of a Covid-19 vaccine, as health officials continued to deliberate over rolling out fourth shots for vulnerable people nationwide.
Officials at Sheba Medical Center, near Tel Aviv, said that their study was the first of its kind in the world and involved administering an additional shot to 150 medical personnel who had received a third dose of the Pfizer-BioNTech vaccine at least four months ago.
The moves in Israel, an early leader in Covid vaccinations, are being closely watched as governments worldwide struggle with how to confront the rapidly spreading Omicron variant, which is driving record numbers of new infections in parts of the United States, Europe and other places. Even as some studies suggest that Omicron infections are milder than those caused by other variants, the surges are already stretching health systems, and experts warn that it could lead to many more deaths.
With studies showing that Covid vaccines still protect people from getting seriously ill from Omicron, a panel of medical experts advising the Israeli government recommended last week that health officials offer a fourth shot for people ages 60 and older, for those with weaker immunity and for medical workers.
The proposal is awaiting formal approval from the Ministry of Health, but questions have been raised about whether the recommendation was premature given the lack of data on the effects of a fourth shot. It was unclear whether the ministry would wait for the results of the hospital study to make its recommendation.
The advisory panel acknowledged uncertainty over the effects of Omicron, but pointed to evidence of decreased immunity in people who were among the first to receive a third dose in August. Israeli data showed a doubling of the rate of infection from the Delta variant, then dominant, among the 60-plus age group within four or five months of the third shot.
Israel, a relatively small country with an efficient public health system, was a leader in introducing the first round of Covid vaccinations and later in giving booster shots, putting it in position to assess early how effective the shots are and how quickly the protection wears off.
Most of the advisory panel argued that the potential benefits of a fourth dose outweighed any risks, and that there was no time to lose in making decisions to protect those most susceptible. But other experts argued that not enough was known about the effects of a fourth shot, and some scientists have raised concerns that too many shots might cause a sort of immune system fatigue, compromising the body’s ability to fight the virus, particularly among older people.
A senior Health Ministry official said last week that the ministry would gather more data from other countries, especially about the risk of severe illness from Omicron among older people, before deciding on whether to offer a fourth dose, and to whom.
On Monday, a second ministry official said that a decision could come within days. Both officials requested anonymity to comment on the process.
Israeli news reports said that the ministry was considering authorizing a fourth shot for people ages 70 and above, instead of 60, and perhaps not for all medical personnel.
The ministry is helping to carry out the study at Sheba Medical Center. Initial results are expected within days.
Prof. Gili Regev-Yochay, director of the infectious-disease epidemiology unit at the hospital, and leader of the study, told reporters that she was a dissenting voice at last week’s meeting of the advisory panel. She said she believed that the recommendation for a fourth dose covered too broad a population and that it was possible that the immunity of many people in their 60s or of younger health workers remained strong after a third shot.
But given the uncertainty surrounding Omicron, she added: “That’s what I think today, but maybe in a week I’ll think differently.”
The highly transmissible Omicron variant is sending daily caseloads in parts of the United States soaring to levels higher than last winter’s pandemic peak.
Delaware, Hawaii, Massachusetts, New Jersey, New York and Puerto Rico are among the areas that have reported more coronavirus cases in the past week than in any other seven-day period, data show.
The numbers point to the ease with which Omicron is spreading across the country, even as some studies from overseas suggest that the variant might cause less severe illness. Experts warn that the surge of infections, combined with the fact that tens of millions of Americans remain unvaccinated, could still create a severe strain on the U.S. health system and lead to many more deaths.
On Friday, before holiday interruptions to data reporting began to affect daily case totals, the seven-day national average of new daily cases surpassed 197,000, a 65 percent jump over the past 14 days. Deaths also increased by 3 percent during that time, to a seven-day average of 1,345, according to a New York Times database.
The national record for average daily cases is 251,232, set in January during a post-holiday surge.
Hospitalizations are up, too, although not as much as cases. Nearly 71,000 Americans are hospitalized with Covid-19, 8 percent higher than the previous week but still well below previous peaks.
From Dec. 5, there has been a fourfold increase of Covid hospital admissions among children in New York City, where the new variant is spreading rapidly, the New York State Department of Health said in an advisory. About half were under 5, and not eligible for vaccination.
Elective surgeries were put on pause at many hospitals after New York’s governor, Kathy Hochul, declared a state of emergency this month.
In Massachusetts last week, Gov. Charlie Baker said he would activate up to 500 members of the National Guard to help in overburdened hospitals. Many other states have done the same.
Government data show that vaccination is still a strong protector against severe illness. Unvaccinated people are five times as likely to test positive and 14 times as likely to die of Covid compared with vaccinated patients, according to the Centers for Disease Control and Prevention.
Still, only 62 percent of Americans are fully vaccinated, and the nation’s medical infrastructure is dangerously frayed two years into the pandemic as hospitals contend with staff shortages fueled by burnout and early retirements. Speaking on ABC’s “This Week” on Sunday, Dr. Anthony S. Fauci, the nation’s top infectious-disease expert, said: “When you have such a high volume of new infections, it might override a real diminution in severity.”
Data out of South Africa and some European countries suggest that Omicron infections have been milder and are producing fewer hospitalizations. But experts warn that might not be true everywhere, adding that the surge in cases may still flood hospitals in many countries.
“Each place has its own demographics and health care system access and, you know, vaccine distribution,” Akiko Iwasaki, an immunologist and researcher at the Yale School of Medicine, said in an interview.
She added that people in England, Scotland and South Africa could have acquired enough immunity from other infections to be able to deal with this variant, or that there could be intrinsic differences in the pathogenicity of Omicron that results in fewer people needing to be hospitalized.
“We cannot assume the same things will happen to the U.S.,” Dr. Iwasaki said. “That is not a reason to relax our measures here, and we still need to vaccinate those pockets of people who are unvaccinated.”
Mikaela Shiffrin, the two-time Olympic champion skier and a top U.S. medal contender at the Winter Olympics in Beijing, said Monday that she has tested positive for the coronavirus and will miss World Cup races Tuesday and Wednesday in Lienz, Austria.
The result complicated Shiffrin’s preparations for the Beijing Games and showed how a surge of cases among competitors could upset China’s and the International Olympic Committee’s efforts to run virus-free Games inside an Olympic bubble. The Olympics are the greatest stage for many athletes, and a positive test can mean the loss of a rare opportunity, just as an outbreak in China could affect the entire Games.
Shiffrin’s announcement came several days after she won a giant slalom race in Courchevel, France, her 72nd career World Cup victory. Shiffrin leads the overall women’s World Cup standings and is first in the giant slalom and second in the slalom.
“I wanted to let you all know that I’m doing well, but unfortunately I had a positive COVID test,” Shiffrin, 26, wrote on Instagram. “I am following protocol and isolating.”
After her win in Courchevel on Dec. 21, Shiffrin spoke of feeling tired.
“It was really quite difficult, to be honest — tiring today! Even after the first run, I wasn’t sure I could do the second run,” she said. “It’s a big push and for every athlete racing. We had to dig very deep and just fight and be aggressive.”
On Instagram on Monday, Shiffrin wished her teammates luck in the races in Austria. “I’ll be cheering for you from afar,” she said.
— Mike Wilson
The Jan. 1 funeral mass for Desmond M. Tutu, the first Black archbishop of Cape Town, will be limited to 100 people because of pandemic restrictions in South Africa.
The archbishop’s remains will be cremated, and his ashes interred at his former church, St. George’s Cathedral, church leaders said during a news briefing on Monday.
The public viewing will be regulated by social distancing rules, in addition to the limited attendance at the funeral mass, where family members and clerics will take precedence on the small guest list, church leaders said.
Coronavirus cases rose exponentially in the country after the detection of the Omicron variant in southern Africa in November. Fortunately, the rates of hospitalizations and death from Covid-19 have not kept pace and cases seem to have peaked in the epicenter of the outbreak, Gauteng Province.
“Please don’t get into a bus to Cape Town,” said Thabo Makgoba, the current archbishop. “We will have to be pastoral and firm and encourage people to watch from home.”
The bells of St. George’s Cathedral rang out on Monday as South Africans began a week of mourning for the cleric, who succumbed on Sunday to cancer at a care facility in Cape Town. One of the most powerful voices in the anti-apartheid movement — and a moral conscience in the decades after the system of institutionalized segregation crumbled in South Africa — his death has been met with an outpouring of tributes in South Africa and from around the world.
The bells of his former church will toll for 10 minutes at noon every day this week, until the funeral mass on Saturday.
— Lynsey Chutel
A Carnival Cruise Line ship returned to Miami on Sunday after multiple people onboard tested positive for the coronavirus, the cruise line said.
The ship, the Carnival Freedom, departed from Miami on Dec. 18 on an eight-day cruise when “a small number on board” were isolated because of a positive coronavirus test, the cruise line said in a statement. The company did not say how many guests or crew members were infected.
“Our protocols anticipate this possibility and we implement and adapt them as necessary to protect the health and safety of our guests and crew,’’ the cruise line said. “This was a vaccinated cruise and all guests were also tested” before the ship departed, the company said.
The cruise line said that “the rapid spread of the Omicron variant may shape how some destination authorities with limited medical resources may view even a small number of cases.”
The ship, which can carry nearly 3,000 passengers and 1,150 crew members, was not able to make planned stops in Bonaire and Aruba and instead made an “alternative visit” to Amber Cove in the Dominican Republic, a company spokesman said.
One passenger shared on Twitter a photo of a letter from the captain who apologized for the stops and said that passengers would receive credit to use toward a future cruise.
The Carnival Freedom is the latest Florida-based cruise to be disrupted as the highly contagious Omicron variant drives up cases in much of the United States and Europe. Many lines have adjusted their rules for masking, testing and vaccines in response to the surge.
Last week, 55 fully vaccinated passengers and crew members on the Royal Caribbean ship Odyssey of the Seas tested positive, the cruise line said. The ship returned to its home port in Fort Lauderdale, Fla., on Sunday. It was the second Royal Caribbean ship from Florida to report positive cases this month, after 48 people aboard the Symphony of the Seas tested positive for Covid-19 during a seven-night Caribbean cruise that departed from Miami.
The company said that all of its crew members were fully vaccinated against Covid-19 and were tested weekly.
As pathology clinics and hospitals across Australia struggle with high demand for coronavirus testing, a clinic in Sydney mistakenly told 400 people that they had tested negative for the virus, when, in fact, they had tested positive.
SydPath, the pathology service of St. Vincent’s Hospital in Sydney, the country’s most populous city, said in a statement on Monday that all those affected had been contacted. But the scale of the mix-up could grow.
The lab also said that 995 more people had been told that they had tested negative, when in fact, their results had not yet been determined. They, too, have been advised of the error and told that their results would be provided by Monday night, SydPath said.
The clinic blamed “a specific human error” for the mix-up and said that procedures had been put in place “to ensure this cannot happen again.”
The errors unfolded amid a surge in coronavirus cases in Australia. On Monday, officials recorded the first death linked to the Omicron variant, a man in his 80s in New South Wales. He had received two vaccine doses and had underlying health conditions, the state authorities said.
SydPath said that the error had occurred “at a time of unprecedented Covid testing activity,” adding that its staff members, as with other pathology teams in New South Wales, were “working around the clock to respond.”
Pathology clinics and hospitals in Australia are struggling to deal with high demand for Covid tests. Tens of thousands of people are lining up every day, either having been identified as close contacts of those with infections or because they require a negative P.C.R. test to travel interstate.
Some residents in the states of New South Wales and Victoria have reported being turned away from busy testing centers, or having to wait three or four days to receive their results.
Queensland and Tasmania require travelers headed into the states to show a negative P.C.R. test within 72 hours of departure. The governments of New South Wales and Victoria have criticized the requirement, saying that it is straining their states’ testing capabilities.
Australia reported a record 9,626 daily cases on Sunday, a 350 percent increase in the past 14 days, according to government statistics and The New York Times’s coronavirus tracker. Most of these cases were in New South Wales, which reported 6,394.
“We would expect that pretty well everybody in New South Wales at some point will get Omicron,” the state’s health minister, Brad Hazzard, said at a news conference on Sunday.
He warned residents not to call an ambulance or to go to the hospital unless they had severe symptoms because of the “enormous pressure” on the health care system.
Perhaps the most pressing question for New York City’s incoming mayor, Eric Adams, is exactly how the nearly one million children and roughly 75,000 teachers will return on Jan. 3 for the start of the spring semester — just two days after Mr. Adams will be sworn in.
Children and staff members are set to head back to 1,600 schools across the city against the backdrop of a dramatic rise in virus cases driven by the Omicron variant, a surge that city officials have said will almost certainly worsen over the next few weeks.
Mr. Adams has said he does not support large-scale shutdowns. “We can’t close down the city anytime a new variant comes up,” he said this week. He has also said that he would support a vaccine mandate for eligible students.
A spokesman for Mr. Adams declined to comment on his specific plans for schools, citing continuing discussions with his team. But Mr. Adams and the incoming schools chancellor, David C. Banks, are weighing a variety of options.
South Korea has given emergency-use approval of Pfizer’s oral treatment for Covid-19, the first pill approved in the nation to treat symptoms of the coronavirus.
Kim Gang-lip, the minister of food and drug safety, said at a news conference on Monday that the treatment, Paxlovid, would “diversify the types of treatment” for the virus and is expected to “prevent serious deterioration of health in patients.”
Supplies of the medication are expected to arrive in the country by mid-January.
The ministry’s announcement came after the U.S. Food and Drug Administration cleared Pfizer’s pill for high-risk patients, which it said last week would be authorized for those age 12 and older. The European Medicines Agency, which regulates drugs in the European Union, has also said that the pill can be used in high-risk adults.
Paxlovid appears to be substantially more effective than a similar antiviral pill from Merck, known as molnupiravir, which was narrowly recommended by the F.D.A.’s advisers for emergency use.
Pfizer expects to manufacture 120 million Paxlovid treatments next year. The company has indicated that the pill would be effective against the Omicron variant.
South Korea’s daily cases reached a record of nearly 8,000 before falling to 4,207 new cases on Monday, the lowest in nearly three weeks. The drop occurred soon after the government reinstated social-distancing rules and limited business hours.
The country has fully vaccinated 82 percent of its population, according to the Our World in Data Project at the University of Oxford.
Having overcome vaccine shortages and inadequate cold storage for shots, Nepal’s Covid-19 immunization drive has now been hampered by another problem: a shortage of syringes.
Nepal’s Health Ministry announced on Monday that a second drive to administer donated Pfizer vaccines to children had been postponed indefinitely.
Sagar Dahal, chief of Nepal’s national immunization program, said that the authorities in the small Himalayan nation had planned to start administering shots to children ages 12 to 17 in eight districts starting on Tuesday. “But we couldn’t arrange syringes for vaccines meant for children and the scheduled inoculation campaign has been postponed for the time being,” he said.
Mr. Dahal added that, although officials had recently scrambled to find five million syringes for other vaccines — the Indian-manufactured Covishield and the Chinese vaccine Vero Cell — they couldn’t arrange the smaller syringes needed for the Pfizer shots, which were the ones to be administered to children.
Health Ministry officials said that they had faced delays in acquiring the syringes both from Covax, a global pool that provides vaccine supplies to poorer nations, and directly from other suppliers.
Badebabu Thapa, a spokesman for the Health Ministry, said that about 15 million additional syringes were needed for the overall inoculation drive, for all vaccines, in children and adults. Nepal has fully vaccinated about 34 percent of its total population of 30 million, according to the Our World in Data Project at the University of Oxford.
In addition to receiving supplies from Covax, Nepal has been acquiring syringes and other medical equipment from China and India. But India is among the countries that have limited the supply of syringes to other countries to meet its own domestic demand, forcing the World Health Organization to warn of a shortfall, particularly in Africa.
— Bhadra Sharma