All appointment slots for Metro's mass vaccination event have been filled, nearly 2 hours after opening WTVF and last updated 2021-03-10 13:45:51-05 NASHVILLE, Tenn. (WTVF) â Just over two hours after opening sign-ups, all 10,000 appointment slots for Nashville's first mass COVID-19 vaccination event have been filled. Sign-ups for Nashville's first mass COVID-19 vaccination event opened on Wednesday morning and the heavy influx of people seeking appointments caused Metro's website to have technical difficulties. Many people attempting to make an appointment for one of the 10,000 slots reported receiving an error when trying to access Metro's COVID-19 website, which is the only way to make an appointment for this event.