Vaccine passports: What are they and how do they work?

Boarding pass, suitcase, passport and ... digital vaccination certificate?

Keen to avoid losing another summer of holiday revenue to the coronavirus pandemic, the European Union, some Asian governments and the airline industry are scrambling to develop so-called COVID-19 vaccine passports to help kickstart international travel. They're working on systems that would allow travelers to use mobile phone apps to prove they've been vaccinated, which could help them avoid onerous quarantine requirements at their destinations.