Europe may soon restrict U.S. tourists again. What does that mean?

Stephanie Flynn had planned to travel from Boston to Italy with her mom to celebrate her 30th birthday. It was April 2020, and the trip didn’t happen due to the COVID-19 pandemic. Neither did their rescheduled getaway last September. Finally, with the world opening up this past spring, Flynn—fully vaccinated—made a third attempt to book her Italy trip, aiming for a September departure.

Then the Delta variant numbers started to creep up in July. 

With fewer than two weeks to go before her departure, Flynn reached out to her travel agent, who expressed no concerns. Less...