Americans returned to the road, skies and stadiums this year. But lately, the great reopening has lost some momentum.

Shows are being canceled, mask requirements are returning to casinos and locales, and consumers are reconsidering their travel plans thanks to a surge in Covid-19 infections.

The reaction to the increased cases isn’t as dramatic as last year, but it has caused travel and leisure executives to notice a recent dip in business.

“It’s people concerned about Delta,” Glenn Fogel, chief executive officer of online-travel agency Booking Holdings Inc., said in an interview this week. The operator of websites like Priceline and Kayak said it saw a slight pullback in booking trends in July compared with June.