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.”
Nearly 2,000 more flights were canceled globally on Monday, including more than 600 U.S. flights, as travel disruptions from one of the year’s busiest weekends for flying spilled into the workweek.
Over the holiday weekend, airlines canceled thousands of flights as the Omicron variant of the coronavirus hit flight crews. The disruptions left thousands of travelers frustrated.
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 across the world were canceled.
While some of the groundings were caused by perennial problems like bad weather and maintenance issues, several airlines acknowledged that the current wave of Covid-19 cases, which has risen in the United States to levels not seen since last winter, contributed significantly.
A JetBlue spokesman, for instance, said 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 just 68 flights, or 1 percent, according to FlightAware, and the cancellations were caused entirely by weather, said Dan Landson, a Southwest spokesman. “We haven’t had any operational issues related to Covid,” he said in an email. Along with United, Delta and American, Southwest is one of the four largest U.S. carriers.
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. The numbers on Christmas Eve and Christmas Day were much higher than the equivalent figures last year, and some figures even exceeded those of the same days two years ago, when virtually no Americans were aware of a virus then 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 was expecting to cancel about 200 flights on Sunday, fewer than the 300 it had predicted a day earlier, according to a spokeswoman, and 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.
“Snow and wintry conditions are creating a bit of a bah-humbug for our operations to and from Seattle,” the company said in a statement Sunday, adding, “We realize it’s incredibly frustrating when travel doesn’t go as planned.”
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.
Retail sales in the United States jumped nearly 11 percent this season compared with the holiday period in 2019, the year before the pandemic upended the global economy, according to a report Mastercard published on Sunday.
The report, Mastercard SpendingPulse, showed an 8.5 percent increase in retail sales over the holiday season, defined as Nov. 1 to Dec. 24, compared with last year. The figures exclude automobile sales.
Sales in stores were up 8.1 percent compared with last year, while e-commerce sales were up 11 percent. Compared with 2019, before the pandemic brought about an explosion of online ordering, e-commerce sales jumped over 61 percent.
Online sales made up 20.9 percent of all retail sales this year, according to the Mastercard report. In 2019, online sales accounted for just 14.6 percent of all retail sales, underscoring how the pandemic has accelerated the shift to e-commerce.
In a statement, Steve Sadove, senior adviser for Mastercard, said many Americans got their Christmas shopping done early this year. “Shoppers were eager to secure their gifts ahead of the retail rush,” he said, “with conversations surrounding supply chain and labor supply issues sending consumers online and to stores in droves.”
Indeed, despite early fears, holiday shoppers received their gifts mostly on time, with many shopping early and in person. Retailers, as well, placed merchandise orders early and tried to head off other bottlenecks. For their part, delivery companies ramped up hiring to handle the deluge of packages, which crushed the Postal Service last year. Nearly all packages delivered this year by UPS, FedEx and the Postal Service arrived on time or with minimal delays, according to ShipMatrix.
While the holiday period starts on Nov. 1 according to the Mastercard accounting, Thanksgiving weekend, the traditional start to holiday shopping, was crucial for retailers. Black Friday, Mastercard noted, was the top day for spending during the holiday season, and spending for the entire long weekend was up 14 percent compared with last year.
— E. Justin Swanson