Estonia has been piloting a digital immunity passport that enabes a person to share one’s COVID-19 status with a third party, such as an employer or authorities, AP reported.

The ImmunityPass mobile and web app collects COVID-19 test data. It was created by a non-governmental organization with the support of Estonian start-up entrepreneurs and medical officials.

The developers say it complies with the Estonian and international data privacy rules, but they acknowledge that “we are well aware of possible ethical, societal and other bottlenecks and why this solution could not work” in some countries.

The World Health Organization has warned against issuing such passports to people who have recovered from COVID-19  because there is no evidence they are protected from a second infection.