People vaccinated against Covid-19 in high-risk parts of the United States should resume wearing masks indoors, the Centers for Disease Control and Prevention (CDC) said Tuesday. The shift comes as the Delta variant of the coronavirus is driving a sharp surge in cases, with hotspots in regions that have lagged behind in vaccinations. “In areas with substantial and high transmission, CDC recommends fully vaccinated people wear masks in public indoor settings,” said CDC director Rochelle […]