Since January, the coronavirus has halted more than 90% of international flights. A survey from the International Air Transport Association found that 40% of recent travelers plan to wait at least six months after the virus is contained to fly again.

To restore confidence among flight passengers, United Airlines announced it will offer customers COVID tests, the first U.S. carrier to do so.

United will start optional tests for customers traveling between San Francisco and Hawaii on October 15th. Passengers will have the option to take a test prior to boarding their flight, and a negative test would allow them to bypass the mandatory quarantine period of 15 days for travelers entering Hawaii.

Customers, who will be responsible for the cost of the test, can choose between a rapid test ($250) administered at the airport or a self-collected mail-in test ($80) prior to their departure.

Until a vaccine is approved and has widespread availability, preflight testing might be the best solution to give people confidence when traveling. Systematic COVID tests of all flyers before departure could also help to influence countries to reopen their borders.