The certificate is essentially a QR code, either on a smartphone or paper, which validates whether a traveler has been vaccinated, has recovered from a COVID infection, or has a recent negative test for COVID-19.
How does the certificate work?
According to the EU, the certificate holder should "in principle be exempted from free movement restrictions," and EU member states should "refrain from imposing additional travel restrictions" on holders "unless they are necessary and proportionate to safeguard public health."
National authorities, such as health care facilities or test centers, are in charge of issuing the certificate, according to the EU.
The EU plans for all 27 member states to accept the certificate, a process made possible by integrating and networking public health data.
Four associated European nations (Iceland, Norway, Switzerland and Liechtenstein), are also included.
The certificate is already accepted in tourist hot spots France, Spain, Italy, Greece and Croatia.
EU Justice Commissioner Didier Reynders said he expected all EU member states to be connected to the certificate network starting Thursday. Only Ireland, which was hit by a cyber-attack targeting its health service in May, will be delayed.
Delta variant complicates travel
However, the spread of the more infectious delta variant of coronavirus could put the brakes on summer travel in the EU.
If cases spike, countries can apply an "emergency brake" provision, suspending the certificate's acceptance.
The delta variant is currently spreading in the United Kingdom and in Portugal, a popular tourist destination.
Last week, Germany announced a ban on incoming travelers from Portugal and Russia, only allowing German residents exemption along with a two-week quarantine. Germany also designated Great Britain as a "virus variant area" at the end of May.
The UK also removed Portugal from its "green list" of destinations.
This week, Portugal, Spain and Malta all abruptly increased restrictions for travelers from the UK, by requiring full vaccination for entry.
wmr/rs (AFP, Reuters)