The U.S. Centers for Disease Control and Prevention has moved away from a broad recommendation that people consider refraining from vaping altogether during the investigation into the outbreak of lung illnesses linked to the practice.

The agency removed from its website guidance that people should stop vaping if they were concerned about the illnesses. The agency first said people should end the use of vaping products in September, but later narrowed that recommendation, warning that people should stop using vaping products...