The EU countries have agreed to allow entry of fully vaccinated third-country nationals. So far this concerns vaccines that have received approval in the Union. Those vaccinated with other drugs will be able to enter the Union members at the discretion of specific host countries. The opening of borders and related vaccination certificates are to become one of the central topics at the emergency Summit of the heads of state and government of the European Union on May 25th. It is planned to approve "green digital passes" in the EU in June. Some countries are planning or already using national vaccination certificates.