Rochelle Walensky, the director of the Centers for Disease Control and Prevention, said Friday that municipalities with low rates of vaccination and increasing coronavirus case numbers should consider imposing mask mandates, warning that the rapidly spreading Delta variant is causing a “pandemic of the unvaccinated.” Stay Connected Forbes on Facebook: http://fb.com/forbes Forbes Video on Twitter: http://www.twitter.com/forbes Forbes Video on Instagram: http://instagram.com/forbes More From Forbes: http://forbes.com