One thing that Delta Air Lines flyers won't need to pack is a vaccination card.
Ed Bastian, Delta's chief executive officer, told CNBC on Tuesday that the airline does not currently plan to require proof of vaccination to fly within the US, citing both challenges with mandating vaccinations not fully authorized by the Food and Drug Administration and the effectiveness of existing safety features on airplanes.
"It's very difficult for us to come in and mandate a vaccine that isn't even federally approved yet, the authorization hasn't been final yet," Bastian said on"Squawk Box," referring to the fact that Pfizer, Moderna, and Johnson & Johnson vaccines are still on emergency authorization. "So stay tuned."
Delta requires new hires to be vaccinated and the majority of the airline's workforce is vaccinated, according to Bastian.
"The vast majority of our customers are vaccinated, they're in a clean environment, they're fully masked," Bastian said. "Our people, over 73% of our staff are fully vaccinated and that number is growing by the day."
Some international destinations do require proof of vaccination to avoid quarantine but the only requirement when flying domestically has been to complete a health questionnaire — for most airlines — and wear a mask in airports and on airplanes.
Bastian's final remark, "stay tuned," hints that the airline may require a vaccine to travel domestically once they achieve full approval from the US Food and Drug Administration. Delta and other airlines had operated select "COVID-tested" flights between the US and Europe where flyers are tested multiple times before and after a flight.
An increasing number of US businesses and localities are now requiring vaccines for some indoor activities. New York City Mayor Bill de Blasio on Tuesday announced that restaurants, gyms, and performance venues would be required to show proof of vaccination. Gyms including SoulCycle and Equinox are also requiring vaccination for members.
Juliette Kayyem, a former assistant secretary of Homeland Security for intergovernmental affairs under the Obama administration, penned an article for The Atlantic calling for the unvaccinated to be placed on "no-fly" lists.
"It will help limit the risk of transmission at destinations where unvaccinated people travel— and, by setting norms that restrict certain privileges to vaccinated people, will also help raise the stagnant vaccination rates that are keeping both the economy and society from fully recovering," Kayyem wrote.
The unfortunately named "Delta" variant of the novel coronavirus has been largely responsible for increasing cases in the US. The former head of the FDA, Dr. Scott Gottleib, believes the Delta variant will peak in late September, as Insider's Dr. Catherine Schuster-Bruce reported in July, at the tail end of the summer travel season.
Airlines for America, the trade organization representing many of the country's largest airlines, didn't take a position on requiring vaccines when reached for comment by Insider but cited multiple studies that show the current effectiveness of aircraft ventilation systems in stopping the spread of COVID-19 onboard airplanes.
"US airlines have leaned into science and research to prioritize the health and safety of all travelers and employees since the onset of the pandemic," an Airlines for America spokesperson told Insider. "In addition to complying with all CDC guidelines and requirements, [Airlines for America] passenger carriers have implemented multiple layers of measures including face covering requirements, pre-departure health-acknowledgement forms, enhanced disinfection protocols and hospital-grade ventilation systems."
"I don't think putting that requirement into domestic travel is going to change much," Bastian said of a vaccination requirement.