To boost international travel, China has launched a digital health certificate programme for citizens with an encrypted QR code that gives authorities a traveller’s health information. QR health codes on smartphone apps are already required to gain entry to domestic transport and many public spaces. The apps track a user’s location and produce a ‘green’ code if a user has not been in close contact with a confirmed case or has not travelled to a virus hotspot. But the system has sparked privacy concerns and fears it marks an expansion of government surveillance. The certificate, launched on 8 March, shows a user’s vaccination status and test results via China’s social media platform WeChat. It will ‘help promote world economic recovery and facilitate cross-border travel’, a foreign ministry spokesman said. Bahrain has introduced a vaccine passport; the USA, UK and EU are considering similar permits.