American Airlines Flight 718, the first US Boeing 737 MAX commercial flight since regulators lifted a 20-month primer in November, will take off from Miami, Florida on December 29, 2020.

Marco Bello | Reuters

American Airlines believes the impact of the coronavirus pandemic will continue to weigh on demand and flight schedules through 2021, the airline’s president said Tuesday.

The Fort Worth, Texas-based airline is flying about 45% of its 2019 schedule this month, Robert Isom told reporters at Miami International Airport, before the Boeing 737 Max’s first U.S. flight carrying commercial passengers ceased almost two years ago .

“We expect it will stay that way through January and February. We hope the vaccine will show promise,” he said.

American and its competitors have warned investors over the past few weeks that a spike in Covid-19 cases and new travel restrictions hurt sales in the fourth quarter, although the number of travelers on vacation rose towards the end of the year.