The big picture: There will probably never be a single credential that most people use to prove they've been vaccinated, for every purpose.
- But the EU's system will help set a standard for a proof of vaccination that's both easily accessible and difficult to forge.
- The U.S. is being closely consulted on the European passport, so any future American system will likely use similar protocols.
Details: Informal mechanisms like simply asking someone whether they're had a shot can suffice in many situations. A system for international travel will likely be far more stringent. And there's a wide middle, too.
- Other activities that don't need the same rigorous standards as international travel could rely on the CDC's vaccination cards; options like a printed QR code, similar to what's been proposed by PathCheck; or a digital QR code, like the ones created by CommonPass or the Vaccine Credential Initiative.
- There may be some state-issued credentials, like the Excelsior Pass in New York.
- A national credential is theoretically possible, and could be linked to the biometric information that already exists on many chipped passports — the World Health Organization is working with Estonia to develop something along those lines — but that would meet steep political resistance in the U.S.
The bottom line: The world of vaccine passports is almost certainly going to end up as a mishmash of different credentials for different activities, rather than a single credential used by everybody for everything.
Go deeper: Americans will likely have to navigate a maze of vaccine "passports"
