Hundreds of people have become sick, several have died, their illnesses all tied to vaping.
Health officials are working to pinpoint whether a particular device, ingredient or additive is to blame.
Meanwhile, President Trump says his administration will propose banning thousands of flavors used in e-cigarettes. Of particular concern are those favored by children. New data shows more than a quarter of high schools students are current e-cigarette users.
Talking about all this are Dr. Ravi Kalhan, director of the Asthma and COPD Program at Northwestern University;s Feinberg School of Medicine, Dr. Kiran Joshi, Senior Medical Officer with the Cook County Department of Public Health and Ruby Johnson, the mother of a college student who became sick.
Watch Pt. 2 of Newsviews: