Walk-in service is available, usually with little or no wait, at the Fairfax County Government Center and the Hyland South County Government Center (Mt. Vernon District Office) vaccine clinics for anyone seeking a COVID-19 booster shot. Hours are Mondays and Thursdays, noon to 5:30 p.m.; Tuesdays, Wednesdays and Fridays, 9:30 a.m. to 3:30 p.m.; Saturdays, 9:30 a.m. to 3:30 p.m. (Government Center only). For more information visit the Health Department’s vaccine page.