IOWA CITY — Over the course of this unparalleled fall semester that forced Iowa’s public universities to tread a fine line between fostering a welcoming college environment and keeping their campuses safe in a pandemic, Iowa State University placed 27 students on deferred suspension for COVID-19 infractions. That put those students under observation for a stint during which — if found in further violation — they could be suspended and thus dropped from ISU for a specific period of time. The University of Iowa, which wrapped its last day of classes Friday, on the semester issued 620 warnings, reprimands, or terms of probation for COVID-related violations — like failure to social distance, wear a mask, follow guest policy guidance, and quarantine or isolate.