The airline's CEO and president informed employees in a letter Friday.
The United States has been facing a COVID-19 surge as the more contagious delta variant continues to spread.
More than 700,000 Americans have died from COVID-19 while over 4.7 million people have died from the disease worldwide, according to real-time data compiled by the Center for Systems Science and Engineering at Johns Hopkins University.
Just 65% of Americans ages 12 and up are fully vaccinated against COVID-19, according to data from the CDC.
Spectator tickets for the Beijing 2022 Winter Games will only be sold to residents of China's mainland, according to the International Olympic Committee.
Participants who are not fully vaccinated will have to serve a 21-day quarantine upon arrival in Beijing.
-ABC News' Christine Theodorou
Of the 1,048 new COVID-19 cases reported to Louisiana health officials since Tuesday, 30% were among children, the state's health department said.
Louisiana currently has 952 COVID-19 patients in hospitals, state officials said.
A total of 13,900 Louisiana residents have died from COVID-19.
Ohio has the nation's second-highest total of pediatric COVID-19 hospitalizations.
As of Wednesday morning, more than 210 children were hospitalized with COVID-19 in the state.
Children appear to be getting sicker than at previous points in the pandemic, according to front-line workers, particularly adolescents who have not been vaccinated.
Dayton Children's Hospital is among those impacted. Hospital officials say they've seen a record number of patients since the end of the summer.
"[It's] pretty hard to keep our heads above water, day in and day out," charge nurse Will Andres told ABC News.
Another concerning trend, doctors say, is the number of children who are forced to stay alone in the hospital because their parents are also battling COVID-19.
Michele Nadolsky, a clinical team leader in the emergency room, added, "One of our biggest concerns is what's going to happen in six months to a year from now, after [the] child has recovered from the acute illness of COVID-19, and what kind of symptoms or long-term effect is it going to have on them."
-ABC News' Arielle Mitropoulos
A government shutdown would sideline important cancer and infectious disease research at the CDC amid the pandemic, former CDC director Tom Frieden told ABC News.
Frieden led the CDC during the Obama administration and through the 16-day government shutdown in 2013.
"Although people who are directly responding to a pandemic would be exempt from furlough, it harms the rest of the agency and makes it harder to do everything ... whether it's answering emails, responding to requests, helping to investigate problems. It has a dampening effect on the agency being to able to do its job protecting Americans," he said.
"The staff at the CDC have basically been fighting the pandemic for 18 months. This would add insult to injury," Frieden said. "We had to furlough people who were working on prevention of cervical and breast cancer ... on the prevention of heart attacks and strokes ... on people collecting data on the health of Americans. And all of that makes people less safe and corrodes agency morale."
-ABC News' Ben Siegel
