▶ Watch Video: CDC cuts COVID isolation in half after airlines cancel thousands of flights over holiday weekend

The shorter COVID-19 isolation and quarantine periods the Centers for Disease Control and Prevention announced Monday are welcome news for airlines. The health agency says that if people are COVID-positive and have no symptoms, they can now isolate for five days instead of 10, and they don’t need a negative test to end that isolation period, but must continue to wear masks for another five days.

The new guidance comes as airlines have had to cancel thousands of flights in the last week, in part because COVID infections left them with a shortage of crew members. 

The airline industry had lobbied for the shortened isolation period, arguing that vaccines and other mitigating measures are widely available, and that the 10-day window worsened personnel shortages.

But Sara Nelson, the president of the Association of Flight Attendants, raised some concerns, saying in a statement, “If any business pressures a worker to return to work before they feel better we will make clear it is an unsafe work environment, which will cause a much greater disruption than any ‘staffing shortages.'”

“We cannot allow pandemic fatigue to lead to decisions that extend the life of the pandemic or put policies on the backs of workers,” she added.

The CDC said data shows the majority of transmission “occurs early in the course of illness,” within two days before symptoms begin and three days after, and White House medical adviser Dr. Anthony Fauci said the new guidance strikes a safe balance.

“If you look at the chance of getting a transmission in that second half of that 10-day period, it’s considerably less than in those first few days,” Fauci said on NBC’s “Nightly News.” “So on balance, if you look at the safety of the public and the need to have society not disrupted, this was a good choice.”

Earlier, Fauci suggested the federal government should consider requiring vaccines for domestic flights.

It remains to be seen when the new CDC guidelines will ease staffing shortages for the airlines.  A few hundred flights were canceled Tuesday, while a few dozen so far have been canceled for Wednesday.

COVID exposure isn’t the only risk for flight attendants — they’ve also borne the brunt of unruly passengers this year, mostly over mask compliance.

On a Christmas Eve flight, two passengers fought over wearing masks. Neither was properly masked during the argument. One woman was taken into FBI custody upon landing.