The news: The European Union’s digital vaccine passport system went live in seven countries yesterday, ahead of a full launch for all 27 member states on July 1. The document, called a digital green certificate, shows whether someone has been fully vaccinated against covid-19, recovered from the virus, or tested negative within the last 72 hours. Travelers who can prove they fit one of these three criteria are not required to be tested or go into quarantine. The certificate is now being accepted in Bulgaria, Croatia, the Czech Republic, Denmark, Germany, Greece, and Poland. 

How it works: The certificate comes in the form of a QR code, which can be either stored on a cell phone or printed out on paper. The data is not retained anywhere afterwards, the commission said, for security and privacy reasons.

Why it matters: As an early mover, the EU could help to lead the way for post-pandemic global travel. The bloc is in talks with the US about how to check the vaccination status of American visitors this summer. That is likely to concern ethicists and data privacy experts, who worry that vaccine passports can be used to further entrench inequity. (To read more about why, check out the full coverage of the issues from our Pandemic Technology Project team.)

Dead end? In any case, it currently seems unlikely that vaccine passports will become common for travel inside the US. Several states, including Alabama, Arizona, Florida, and Georgia, have banned them. New York’s Excelsior Pass, America’s first government-issued vaccine passport, has been downloaded more than one million times, but that represents just a small proportion of the 9 million people who’ve been vaccinated, and the vast majority of businesses aren’t using it yet.

Even early movers are ditching them. Israel was one of the first countries to roll out a vaccine passport. Its “green pass” was designed to allow access to restaurants and sporting events for those who could prove they were vaccinated. But as the country’s successful  vaccination rollout has driven coronavirus numbers down into double figures, Israel this week scrapped the pass as it moves to open up fully for everyone.