Flight disruptions continue with thousands more cancellations as Omicron thins airline

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 only a few cancellations related to crew exposures to the coronavirus, said a spokeswoman, Alexa Rudin. Yet it 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.

The pandemic has also caused a shortage of train and bus workers nationwide. In New York City, the Metropolitan Transportation Authority is also dealing with an uptick in positive cases among its staff, which is 80 percent vaccinated. It said subway service on Monday was running on a normal schedule, with scattered exceptions.

“Whatever we can do as riders to help minimize the risk to transit workers will help to reduce the spread,” said Lisa Daglian, the executive director of the Permanent Citizens Advisory Committee to the M.T.A., a watchdog group. “The M.T.A. is doing what it can with the resources it has available.”