• Delta will start selling all seats on its flights starting May 1.
• The carrier is the last U.S. airline to end the policy, which it first put in place in April 2020.
• The Atlanta-based airline introduced a host of other changes, including extending ticket validity until the end of 2022.

Delta Air Lines said Wednesday it will stop blocking seats on its planes starting May 1, the last U.S. airline to end the Covid-19-era policy as more travelers return to the skies.

Delta first started blocking middle seats and limiting capacity on smaller planes in April near the start of the pandemic. Other airlines had similar policies, including Southwest Airlines, JetBlue Airways and Alaska Airlines, but they have since gone back to selling all seats.

Southwest in January estimated it had an $80 million revenue boost from opening up all seats a month earlier.

Physically distancing from other passengers is extremely difficult on an airplane. Delta and other carriers have repeatedly said filtration systems and intense cleaning make it unlikely that travelers will catch Covid-19 on a plane. But Delta said many travelers choose Delta over other airlines because it kept its policy in place.

CEO Ed Bastian said in announcement that 65% of customers who flew Delta in 2019 said they expect to have at least one dose of a Covid-19 vaccine by May 1 and that that is "giving us the assurance to offer customers the ability to choose any seat on our aircraft, while also introducing new services, products and rewards to support the journey."

The change comes as what is shaping up to be a better summer travel season than last year approaches. Generally the most lucrative time of year, airlines suffered last summer as many potential customers stayed home.

Delta's President Glen Hauenstein told attendees at a JP Morgan conference this month opening up middle seats would be "an incredibly strong lever for us with very minimal cost to open those seats up."

With vaccines rolling out across the country, airline executives are upbeat about an increase in bookings for late-spring and summer trips, though business and international travel continues to suffer.

United Airlines CEO Scott Kirby on Wednesday told a U.S. Chamber of Commerce aviation conference that domestic leisure demand has "almost entirely recovered." American Airlines on Monday said bookings were back to 90% of 2019 levels in the week ended March 26 and that it plans to take most of its planes out of storage to meet demand in the second quarter.

Delta announced a host of other changes aimed to drum up revenue. Customers with reservations that had been valid until the end of 2021 or who bought tickets this year will be able to use them until the end of 2022.

Delta also said its customers can earn as much as 75% more to get to Medallion status. The carrier and its rivals' frequent flyer programs have become more important during the pandemic. These programs make money by selling miles to banks, which customers earn when they use rewards credit cards. Delta last year raised a then-record $9 billion in debt backed by its SkyMiles program.

The carrier also said that in early June it will offer hot meals in its Delta One or first-class cabins on some transcontinental flights. Boxed meals will be offered on some other domestic routes for first class in July.