What did we learn from the vaping lung injury outbreak?

In 2019, a wave of serious lung injuries swept across the United States, and all the cases had one thing in common: the people affected had used e-cigarettes or vaped. Health officials scrambled to track the outbreak, documenting where cases appeared and what the patients were like. This report summarizes those patterns and characteristics—it's essentially a snapshot of what the outbreak looked like as it unfolded. Because this is an observational report, it doesn't prove what caused the injuries or tell us how many people were ultimately affected. It simply captures the concerning picture that was emerging at the time.