(CNN) — While the number of people flying out of US airports this year has matched, and at one point exceeded, 2019 levels, Christmas Eve air travel fell sharply below pre-pandemic levels.
Thousands of Christmas weekend flights were canceled at the last minute because of staff and crew calling out sick amid the Omicron surge. The new variant has become the dominant strain of coronavirus in the US. More than 1.7 million people passed through Transportation Security Administration (TSA) checkpoints Friday, TSA spokesperson Lisa Farbstein said on Twitter. This is more than 800,000 fewer people than the nearly 2.6 million screened in 2019 before the coronavirus pandemic.
That number is still higher than the 846,520 people the agency screened on Christmas Eve of 2020.
Less than three weeks after Omicron was first detected in the US, it accounted for over 73% of all new cases as of Monday, according to data from the US Centers for Disease Control and Prevention.
In spite of rising coronavirus cases, millions are still flying with the TSA reporting 2.19 million people screened at airports across the country on Thursday, the highest figure since the uptick in holiday travel started a week ago.
On Wednesday, there were more people traveling through US airports than in 2019.
Globally, airlines have canceled about 5,700 flights on Christmas Eve, Christmas Day and the day after, according to FlightAware. That includes about 1,700 flights within, into or out of the United States.
Health officials recommend third booster shots
In the last few weeks, reacting both to Omicron and clear evidence of fading immunity to the Delta variant after six months, public health authorities strongly encouraged the already vaccinated to receive a third dose -- the booster -- pronto. Adding the third shot clearly is effective against Omicron as well, with National Institutes of Health data on the Pfizer vaccine showing that protection after three doses can reach about 80% effectiveness. Preliminary data from Imperial College London on both mRNA vaccines used in the US places the protection from a third dose between 55% and 80%.
As former NIH director Francis Collins and UK leaders noted, booster-induced immunity is also critical for reducing the risk of severe symptoms, even if a breakthrough infection should occur.