International Travel Opens To The Vaccinated, But How Do You Prove You Got The Shot? at 6:23 am NPR There's good news and bad news for Americans who have been itching to take a European vacation. Spain reopens to vaccinated tourists on June 7. Greece, Germany, France, Italy, Croatia and other countries are opening up again soon, too. But in order to go, travelers will have to show proof that they've been vaccinated and it's not clear yet how they'll do that. And that's causing a lot of confusion among those with pent up wanderlust, as demand for air travel has been soaring in recent weeks.