https://www.reuters.com/article/us-health-coronavirus-eu-privacy/vaccine-passports-must-be-proportionate-legal-eu-privacy-watchdogs-say-idUSKBN2BT1K0 >Plans by European Union countries to issue certificates showing that citizens have been vaccinated against COVID-19 should have a legal basis to ensure that they are necessary and proportionate, the bloc's privacy watchdogs said on Tuesday.