The intense medical care required for four Minnesota teenagers who developed severe lung illnesses linked to vaping is stunning.

Among the interventions: extensive hospital stays, sometimes in the intensive care unit and sometimes requiring intubation to help the young patients breathe. After discharge, ongoing monitoring is needed to determine if the illness leaves lasting lung damage. All of this in young people who should be in the prime of their lives and their health.

Up to 50 cases of similar lung injuries have now been reported in e-cig users across the nation, with an alarming number in young adults. Health officials have stopped short of saying vaping, which involves inhaling nicotine vapor from an electronic “e-cig” device, is the cause. But they’ve been unusually pointed in their remarks. Policymakers in Minnesota and elsewhere are grossly negligent if they fail to note that directness and act upon it.

“We have no leads pointing to a specific substance other than those that are associated with smoking or vaping,” Dr. David D. Gummin, professor and chief of medical toxicology at the Medical College of Wisconsin, said in an Aug. 14 New York Times story.

In early August, health officials in Gummin’s home state reported that 11 teens and young adults had required hospitalization for vaping-associated lung injuries. In addition to nicotine, the vapor may contain other chemicals that irritate or damage lung tissue. There are now four more confirmed cases in Wisconsin, with 15 additional illnesses in a broader age range under investigation there. Cases also have been reported in Illinois, and investigations are underway in New York, Indiana and California.

So far the number of hospitalizations is relatively small, but that is of little comfort given vaping’s embrace by adolescents and young adults. Former U.S. Food and Drug Administration Commissioner Scott Gottlieb rightly called e-cig use in young people an “epidemic.”

“From 2017 to 2018, there was a 78% increase in current e-cigarette use among high school students and a 48 percent increase among middle school students,” Gottlieb said in 2018.

The widespread use leads to this disturbing deduction about vaping-related illnesses. “This is just the beginning of adverse health reports,” said Dr. Richard Hurt, a retired Mayo Clinic tobacco addiction expert, in an interview with an editorial writer. Hurt also warned that there could be other damaging health effects that don’t show up for years or even decades.

Gottlieb merits praise for grasping vaping’s risks far ahead of the curve. He took serious steps to stem e-cigs use in young people. One key move: banning e-cig products, such ones that produce candy- or fruit-flavored vapors, in many retail settings.

Unfortunately, Gottlieb resigned March 5. No permanent replacement has been named, a situation that President Donald Trump needs to swiftly fix. Gottlieb’s successor must be committed to carrying on his e-cig campaign.

State lawmakers also need to act. Raising the tobacco and e-cig purchase age from 18 to 21 would be a logical first response. It’s important to note that all four of the Minnesota young people who became ill are teens. Moving the purchase age to 21 would protect older teens from getting hooked on nicotine and keep e-cigs out of the hands of even younger users who might rely on friends to buy the products for them.

The Minnesota Legislature considered but failed to pass a measure bumping the purchase age to 21. That looks particularly irresponsible as these illnesses come to light. The measure should be reintroduced and passed early next session, giving lawmakers time to consider other consumer safeguards against a product whose serious risks are just starting to become clear.