Doctor explains the importance of mask wearing even for non-Covid related viruses

SAN ANSELMO, CALIFORNIA - JULY 28: 3M brand N95 particulate respirators are displayed on a table on July 28, 2020 in San Anselmo, California. 3M reported second quarter earnings that fell short of analyst expectations and showed overall sales falling 12.2 percent to $7.18 billion despite a ramp-up in sales of N95 face masks due to the coronavirus COVID-19 pandemic. (Photo Illustration by Justin Sullivan/Getty Images)