Masks are back in high demand: "We can't keep them on shelves longer than a day"

Mask shortages could loom once again as the highly contagious Delta variant continues to spread across the U.S. and more individuals start to heed renewed government advice to wear masks indoors and in high-transmission settings again. 

Some cities, states and businesses have implemented mask mandates, too, helping to drive up sales of cloth and surgical masks as well as medical-grade respirators, once reserved for hospital and frontline workers.  Demand for different mask varieties has soared over the past few weeks in tandem with a sharp rise in COVID-19 case numbers tied to the Delta variant of the coronavirus, according to manufacturers and market experts.