Gov. Parson to visit St. Louis mass vaccination site, discuss event hosted by FEMA Beginning on Wednesday, April 7, a mass vaccination site, located at the Dome at America’s Center in St. Louis, will allow up to 3,000 people to be vaccinated a day, seven days a week, in an eight week period. (Source: WAFB) By Marsha Heller | April 5, 2021 at 6:29 AM CDT - Updated April 5 at 6:29 AM ST. LOUIS, Mo. (KFVS) - Governor Mike Parson is scheduled to make a stop at a mass vaccination site in St. Louis on Monday, April 5. Gov. Parson will be delivering remarks during a news conference at 3 p.m. on the event being held at the The Dome at America’s Center Convention Complex.