The EU's planned digital "green pass" showing the status of vaccinated people will probably only take into account jabs authorised by the bloc's medicines regulator, a top official said on Friday.
The European Medicines Agency has so far authorised four COVID vaccines - from BioNTech/Pfizer, Moderna, AstraZeneca and Johnson & Johnson - so, unless this changes, the pass might not record a jab with Russia's Sputnik V, for example.
"What we would like to create is a digital certificate where you can have your negative PCR test or prove that you have antibodies or that you have been vaccinated by a vaccine that has been approved by EMA," the EU commissioner for home affairs, Ylva Johansson, told journalists.
The European Commission is to unveil its proposal for the green pass next Wednesday, with legislation to be sent to the European Parliament.
EU chief Ursula von der Leyen has said she hopes it would allow people "to move safely in the European Union or abroad - for work or tourism".
The EMA is currently reviewing data related to Russia's Sputnik V vaccine as well as ones from Novavax and Curevac for safety and efficacy to see whether they too might be authorised.
The EMA is not currently looking at China's COVID vaccines - despite the prime minister of EU member country Hungary, Viktor Orban, saying he had been injected with one of those, the Sinopharm jab.
Even if EMA authorises a COVID vaccine, that does not mean that the European Commission will approve it for use across the 27-nation European Union.
The EU executive also weighs vaccine-makers for their ability to scale up production and whether they have manufacturing lines in the EU, under European jurisdiction.
The commission has already expressed wariness about the Sputnik vaccine and has indicated it is unlikely to add it to its portfolio of EU-wide approved jabs, even if the EMA gives its nod.
Utilisation of an EU green pass has not yet been defined.
Some tourist-dependent countries such as Greece and Cyprus want it to be used to unlock virus travel restrictions.
But France and Germany are cautious, not wanting it to become a tool for discrimination, especially as younger EU citizens probably won't be immunised until late this year or even next year.
The commission is also concerned that new variants that mute the effectiveness of current vaccines could limit their usefulness.