European airlines hoping to extend the holiday season are running up against the start of the school year that is denting family bookings, while the spread of the delta variant of Covid-19 prompts new travel curbs.

This spring, Florida Gov. Ron DeSantis issued an executive order forbidding businesses from making their patrons prove that they have been vaccinated against the coronavirus. He also signed into law a bill to give the ban more teeth, threatening violators with fines in the thousands of dollars.