The European Union started rolling out a first-of-a-kind digital health certificate that permits people who have been vaccinated to travel freely within the bloc without the need to quarantine or test negative for Covid-19 upon arrival at their destination.

About 200 million certificates have been generated among a population of about 450 million. The documents contain data on whether a passenger has received a vaccination, or has had a recent negative Covid-19 test, or proof of antibodies. The European Commission, the EU’s executive arm, has told governments they must grant quarantine-free entry to EU travelers carrying the documents.

European citizens and noncitizens legally living in the EU can access the document, which contains a scannable QR code, online. Depending on the national system in place, the document can be downloaded to a mobile app or printed. States are required to provide scanning devices to verify the documentation.

Airlines are hoping that the system will mark the beginning of a recovery in short-haul flying within Europe. A bounce in air travel has trailed recoveries seen in bigger domestic markets including in the U.S. and China.

“This is the bit we’ve been pushing for the last number of weeks,” Michael O’Leary, chief executive of discount carrier Ryanair Holdings PLC, Europe’s biggest airline. “There is an explosion of vaccination going on all over Europe.”