The U.S. remains unprepared for a world that is now, and soon will be even more, mandating use of vaccine passports for travel.
The only “proof” available in the U.S. is an easily forge-able, unverifiable paper vaccine card.
Elsewhere nation’s have set up verifiable, authenticated vaccination passport records.
As global travel slowly re-opens to vaccinated travelers, U.S. citizens will remain at a disadvantage because of the incompetence of public health to plan ahead for this need. Public health remains AWOL on this issue.