As travelers across the U.S. have been surprised to find their flights canceled this week amidst the holiday season, cases of the omicron variant of the coronavirus and flu hospitalizations are on the rise.
More than 1,000 flights around the country were called off because crews were sick with COVID-19 – and recent storm fronts created additional chaos.
Flight tracker FlightAware showed that U.S. airlines canceled more than 4,000 flights, both domestic and international.
United Airlines said it canceled 115 flights on Monday due to crews with coronavirus and Delta Air Lines was expected to nix more than 200 flights after scrapping more than 370 on Sunday.
Data from the Transportation Security Administration (TSA) shows that the number of passengers screened climbed significantly from last year, but was still generally short of 2019 levels.
The agency has forecast that the Monday after New Year's will be one of the busiest days of the season and new quarantine guidelines from the U.S. Centers for Disease Control and Prevention (CDC) could aid airlines and travelers alike.
On Monday, the CDC shortened the isolation restrictions for people who have the virus from 10 to five days. A call from airlines for the Biden administration to shorten the quarantine period had been disputed by the union for flight attendants.
In addition, National Institute of Allergy and Infectious Diseases (NIAID) Director Dr. Anthony Fauci said Monday that the nation should seriously consider a vaccination mandate for domestic travel.
Fauci warned that omicron would "get worse before it gets better," and while much still remains unknown about the variant, infections have jumped around the world.
In Britain, hospital admissions were up more than 70% on Christmas from a week earlier and other European leaders announced stringent measures in an effort to curtail the spread.
Greece recorded its highest-ever one-day total of new infections.
New York City's iconic Times Square New Year's Eve celebration will be scaled back this year, hosting approximately 15,000 people down from 58,000.
In a press release, Mayor Bill de Blasio's office said last week that visitors won't be allowed entry to the area until 3:00 p.m. EST.
"New Yorkers have stepped up tremendously over the past year—we are leading the way on vaccinations, we have reopened safely, and every day we work toward building a recovery for all of us," the mayor said in a statement. "There is a lot to celebrate and these additional safety measures will keep the fully vaccinated crowd safe and healthy as we ring in the New Year."
"New York is the best place in the world to celebrate New Year’s Eve and now it will be one of the safest against COVID as well," said Mayor-elect Eric Adams. "The mayor has made the right move to take precautionary measures as we learn to live with COVID and fight the omicron variant—and New Yorkers and visitors alike can now enjoy Times Square and the rest of our city as we ring in 2022."
All of this comes as the 2021 flu season has arrived on schedule, with two child deaths reported.
The most intense flu activity was in Washington, D.C., according to the CDC.
The CDC's Lynnette Brammer told The Associated Press that the type of virus circulating now tends to cause the largest amount of severe disease, especially in the elderly and very young.
Last year's flu season was the lowest on record, with only one child death in 2020.
Vaccination is the best way to protect against the flu and against COVID-19. Booster shots against the coronavirus trigger a big jump in virus-fighting antibodies.
The Associated Press contributed to this report.