Global airline carriers have cancelled more than 2,000 flights so far on Christmas Eve, in an indication of how the Omicron coronavirus variant is affecting holiday travel.
2,028 flights around the world had been scrapped, the website FlightAware showed as of 1.20pm Irish time on Friday.
In the United States, hundreds of Christmas Eve flights were cancelled by United Airlines and Delta Air Lines as Omicron took a toll on its flight crews and other workers.
Delta cancelled 138 flights and United Airlines cancelled 170 flights, data from FlightAware showed as of 2.22pm Irish time.
However, most flights went ahead, as millions of Americans put aside their concerns over infection and ploughed ahead with their holiday plans.
Holiday travel
Covid-19 infections have surged in the US in recent days due to Omicron, which was first detected in November and now accounts for nearly three-fourths of US cases and as many as 90 per cent in some areas, such as the Eastern seaboard.
The average number of new Covid infections has risen 37 per cent to 165,000 per day over the past week, according to a Reuters tally.
Daily totals of deaths and hospitalisations, considered lagging indicators, were little changed nationwide over the past seven days, but have jumped 55 per cent and 28 per cent, respectively, over the course of December.
Anticipating an even larger flood in cases requiring medical attention, the Centers for Disease Control late Thursday cut its recommended quarantine period for Covid-positive healthcare workers who are asymptomatic to seven days from 10.
While Americans scrambled for Covid-19 tests and weighed varying public health guidance about how to gather safely, many were determined to enjoy some semblance of holiday celebrations and tradition.
New Year celebrations
The Transportation Security Administration on Wednesday screened 2,081,297 passengers through the nation's airports, an increase of 144,000 over the number of travellers it screened pre-pandemic on the same date in 2019.
US health officials have said people who are fully vaccinated should feel comfortable proceeding with holiday travel and family gatherings. They warned those who are unvaccinated are at higher risk of getting seriously ill or dying from the virus.
Omicron's rapid spread will also put a damper on New York's iconic New Year's Eve celebration for a second straight year. Mayor Bill de Blasio said attendance for the midnight ball drop in Times Square will be capped at 15,000, roughly a quarter of the typical pre-pandemic crowd size.
Many New York holiday visitors planned to limit themselves to much smaller gatherings.
Madeleine Kennedy, a ski instructor from Lake Geneva, Wisconsin, flew to New York on Thursday armed with a trove of Covid testing kits as she prepared to spend Christmas with her family in the borough of Queens.
It will be a scaled-down affair this year, with guests required to take Covid tests before gathering, she said, and with some relatives spending the holidays in Chicago.
“The second time around, I think the world is less shocked and I think we're going to be able to plough through this,” Ms Kennedy said.
