Hospital staff world-wide are demoralized after seven months of virus-fighting triage. The wartime rhetoric that world leaders initially used to rally support is gone. Family members who willingly sealed themselves off during spring lockdowns are suddenly finding it hard to resist the urge to reunite.

Zoe Sharp, a 43-year-old human-resources leader in Washington, D.C., has been stringent with her family throughout the pandemic, sanitizing elevator buttons, airing out packages and microwaving the newspaper. Her 4-year-old son Hank even created a no-cuddle list to protect family members who are more vulnerable to the virus, like his grandparents.

A week ago, however, something snapped. Ms. Sharp booked a trip to visit her father-in-law in Memphis, Tenn., replete with a stop at the local theme park. Grandpa is now off the no-cuddle list.

“I need something to look forward to,” Ms. Sharp says, adding that her children “want to see their grandfather. They’re worried about him, and they talk about him a lot.”