Airlines in the US are already in the process of leveraging apps and smartphones to allow travelers to offer proof that they have been vaccinated, or recently tested negative for COVID-19, and they're not alone: Across Europe, a growing number of airlines and countries are adopting, or leaning toward adopting, so-called "vaccine passports".
France24 reports Wednesday that countries increasingly see these vaccine passports as the best chance to bolster hard-hit tourism industries in places like Spain and Greece. However, since vaccines are still relatively hard to come by in Europe (supplies in the developing world are also scarce) there are concerns that vaccine passports won't work - while also raising thorny privacy issues.
Most programmes under development are geared towards facilitating travel and come in the form of smartphone apps with varying criteria for a clean bill of health.
Vaccine passports, for example, are a popular way to approach proof of immunity with jab rollouts underway across the globe.
While UK Prime Minister Boris Johnson recently told Britons that they won't need a vaccine passport to visit the local pub, his French counterpart Emmanuel Macron is considering creating a digital vaccine passport without which French citizens might be barred from visiting restaurants and other public places.
French President Emmanuel Macron recently suggested yet another, more localised form of Covid-free permission slip: the so-called "health pass."
This certification would only be valid within France's borders but would allow a fully vaccinated person to, for example, eat in restaurants and attend certain events.
Fortunately, vaccine passports aren't the only option available to airlines hoping to fight the spread of COVID.
There are also apps that accept positive antibody tests as proof of immunity for those who have had the virus and recovered.
But the World Health Organization has warned that there is no evidence to show that recovered Covid sufferers with antibodies are protected from a second infection.
Even as pressure to implement passports grows, the report notes that vaccine passports do raise some thorny legal issues, while also potentially exacerbating economic inequality as the poor are effectively barred from traveling, while their movements in public are limited.
Making health passports stricter or requiring them for travel could invite legal challenges.
A major worry is that banning unvaccinated people from travelling would exacerbate inequality since access to jabs is far from universal.
There are also concerns over how applications would access users' personal data.
In France, there is already an official database of citizens who have been vaccinated against Covid-19, approved by the country's privacy watchdog.
However, the body has warned it will re-examine the issue should the database be put to use in the context of a health passport.
Earlier this week China launched a digital "health certificate" for its 1.3 billion citizens which will record their vaccination status and COVID test status.
In tourism-dependent Greece and Cyprus, vaccination passports are being launched specifically for travel to and from Israel, which has fully vaccinated 44% of its population, and, being situated on the east coast of the Mediterranean, is also located nearby. Denmark and Sweden are also looking to launch health passports soon, while the EU is promising to propose a "green pass" to ease movement within the bloc.