EXPLAINER: How vaccine passports for global travel will work

LONDON (AP) — Boarding pass, suitcase, passport and ... digital vaccination certificate?

Keen to avoid losing another summer of holiday revenue to the coronavirus pandemic, the European Union, some Asian governments and the airline industry are scrambling to develop so-called COVID-19 vaccine passports to help kickstart international travel.

They're working on systems that would allow travelers to use mobile phone apps to prove they've been vaccinated, which could help them avoid onerous quarantine requirements at their destinations.

But the multiple efforts underscore the lack of one central international system to electronically verify vaccination status. The projects also face technical challenges in working together, while questions about privacy and vaccine inequality linger.

Vaccination passports would add another digital layer to the multitude of existing coronavirus health and contact tracing apps many countries and U.S. states have rolled out. Their use domestically to reopen local economies has been hotly debated, with many opposed to requiring them for pubs, concerts and sporting events. However, there's more momentum to use them for international travel, especially as countries like Iceland open their borders to vaccinated visitors and others like Saudi Arabia start allowing vaccinated citizens to travel abroad. The EU's decision last week to open its borders to fully vaccinated travelers adds even more urgency.

Here's a look at how vaccine passports work:

OFFICIAL EFFORTS

The first part of a vaccination passport is the user's official or approved electronic immunization record.

The European Union, China and Japan are all working on their own digital vaccination certificates for cross-border travel. The U.K., meanwhile, updated its National Health Service...