A 15-year-old in Cambridge, Mass., shows off her vaping device in 2018. Schools and health officials across the U.S. are struggling to curb what they say is an epidemic of underage vaping.

A 15-year-old in Cambridge, Mass., shows off her vaping device in 2018. Schools and health officials across the U.S. are struggling to curb what they say is an epidemic of underage vaping.