European Union countries introducing their own COVID vaccination certificates would have to grapple with a myriad of disjointed systems if the bloc fails to build a shared one, a senior official said on Wednesday. The EU is pushing to have a shared digital health pass to allow tourists to travel freely this summer. But discussions are not yet settled on costs, data and privacy issues, as well as technical and medical aspects of the new system. "If we can deliver politically, the technical solution will be ready in time. If we don"t, we risk fragmentation across Europe, with a multitude of possibly incompatible national solutions," EU Justice Commissioner Didier Reynders said. "We would risk having a variety of documents that cannot be read and verified in other member states. And we risk the spread of forged documents, and with it, the spread of both the virus and the mistrust of citizens," he told the European Parliament. Tourism-reliant southern EU countries like Spain and Italy are keen to launch the new tool as soon as possible to help economies that have been mauled by the pandemic. But they face a more reluctant north, as well as complex EU decision procedures. With no central gateway to ensure interoperability yet in place, countries including Estonia, Lithuania, Greece, Spain, Germany and France, are introducing their own solutions to record vaccinations. DRY RUN Commission officials told a separate briefing that the gateway - which would allow officials in one EU country to check the health pass of a visitor from elsewhere in the bloc - would enter testing next month. Twenty member states will be ready to join the trial phase with a view to making it possible to go fully live by mid-June. The technology for the digital passes is secure and no sensitive personal data would be shared, the officials said. Disputes between EU countries over supplies of medical equipment, drugs and vaccines have already complicated the bloc"s joint response earlier in the pandemic. As it now faces a third wave of infections, sceptics say discussions about restarting free travel are premature given low vaccination levels. The rushed implementation of the joint system raises questions over how visitors from overseas will be handled. Questions also remain over which vaccines they would honour, with a distinction between those approved for the EU by the European Medicines Agency and those like the Russian or Chinese jabs that might only be allowed by some countries. Another issue is whether antibody tests provide adequate proof that a person who has recovered from COVID-19 is immune. EU countries including Belgium also worry about discriminating against those who would not get the jab. Our Standards: The Thomson Reuters Trust Principles.