Study finds mask mandates slow coronavirus spread while dining out increases cases Published March 5 Share on Facebook Print article NEW YORK — A new national study adds strong evidence that mask mandates can slow the spread of the coronavirus, and that allowing dining at restaurants can increase cases and deaths. The Centers for Disease Control and Prevention released the study Friday. “All of this is very consistent,” CDC Director Dr. Rochelle Walensky said during a White House briefing on Friday. “You have decreases in cases and deaths when you wear masks, and you have increases in cases and deaths when you have in-person restaurant dining.”