Community vax clinic in Yellowstone County to close at end of May Walk-ins still welcome By: Mitch Lagge and last updated 2021-04-28 20:14:38-04 BILLINGS â While walk-in appointments are still plentifully available, the Yellowstone County Unified Health Command will close the doors of the community vaccination clinic at the Shrine Auditorium at the end of May. First doses will continue at the Shrine through the week of May 10. Following that date, people can no longer get a first dose at the clinic. Second dose clinics wrap up the week of May 31, according to a press release from the Unified Health Command.