As vaccinations increase and the reopening continues, the battered travel industry is getting back in the air. But unsurprisingly, the recovery is once again K-shaped — some sub-sectors are doing much better than others.

According to Jefferies senior research analyst Sheila Kahyaoglu, total U.S. airline traffic is around 40% of what it was at the same time in 2019. But the difference between destinations is stark: international is down 67% and domestic is only 22% lower.

"International is still quite weak," Kahyaoglu told Yahoo Finance Live.

Because of this, domestic airlines like Southwest (LUV) have been seeing much better numbers compared to the larger airlines that fly broader routes out of the country. This appears to be somewhat of consensus right now, due to the discrepancies of the U.S. vaccination campaigns versus the rest of the world that still waits. (Airlines are becoming creative around incentivizing vaccinations.)

According to Cowan managing director Helane Becker, the airlines “best positioned” now are Spirit, Allegiant, Frontier, Southwest, and also American, though it has a little more international exposure than the others.

“If we’re wrong and international comes back faster than we think, United is the one that benefits the most,” she said. To bet on the international recovery, she added, “you would own United, because they’re 50% domestic, 50% international.”

Getting back to 2019 levels may not happen without that international travel, as well as the other key laggard — business travel.

“I think it’s going to be difficult for us to get back to 2019 without some international and business traffic coming back,” Becker said. “We don’t think that will happen before 2023.”

Still, some people are banking on this.

“Investors right now are starting to transition to international, because international hasn’t worked yet,” Kahyaoglu said. Going forward, if Europe is on the table for Americans’ vacation plans, that could change the airline landscape.

An interesting timing situation

In a note published Tuesday, DataTrek’s Jessica Rabe dove into some of the data on airlines. In the airline industry, supply and demand move ticket prices in an almost instantaneous fashion because of the algorithmic nature of pricing, which makes for a very public dataset to look at supply and demand. To find out demand for Thanksgiving flights, for example, you just need to go through the motions of booking a flight. If they’re cheap, that tells you something about the demand — especially when coupled with Google searches.