http://www.sciencemag.org/news/2021/08/what-does-delta-variant-have-store-us-we-asked-coronavirus-experts > Crowds on Bourbon Street in New Orleans in late July. The coronavirus Delta variant is driving record-breaking case counts in Louisiana and other states. > The United States is standing at a dire inflection point, with pandemic coronavirus cases surging and only 50% of the population fully vaccinated. Driving the latest wave is the highly contagious Delta variant, which according to the Centers for Disease Control and Prevention (CDC) caused between 80% and 87% of all U.S. COVID-19 cases in the last 2 weeks of July — up from 8% to 14% in early June. The variant’s exceptional infectiousness has driven cases from a 7-day average of 13,500 daily cases in early June to 92,000 on 3 August. At the same time, an internal CDC document that leaked last week says the variant may make people sicker, citing published reports from Singapore and Scotland and a preprint from Canada.