Two Centers for Disease Control and Prevention (CDC) studies published today in Morbidity and Mortality Weekly Report track COVID-19 spread on US college campuses, one showing that 101 counties with large universities offering in-person instruction saw a 56% jump in coronavirus cases after classes began, the other finding that 91% of gatherings at an Arkansas university were tied to fraternity and sorority activities.Remote learning linked to drop in casesThe first study showed that counties with large, nonprofit colleges and universities conducting only remote learning experienced a 17.9% drop, on average, in new COVID-19 cases in the 21 days before and after the start of fall classes.