Registration opens for St. Louis County COVID-19 vaccination event on UMSL campus Sam Clancy Replay Video UP NEXT The Missouri National Guard, Governor Mike Parson's office and local health officials will host their first COVID-19 vaccination event in St. Louis County Saturday. The event will be held at the Millennium Student Center on the campus of the University of Missouri St. Louis from 9 a.m.-7 p.m. or until supplies run out. Approximately 2,200 doses are expected to be administered at the event, which will be in addition to the county's allotment from the state, according to a news release from the St. Louis County health department.