Three teams of nurses, who had vaccinated each other on Dec. 23, when the doses arrived at the health department (also in the midst of a snowstorm), rolled vaccination carts from car to car administering the shots.

“It went really, really smoothly,” says Mueller. “We vaccinated people in the first 13 cars in about 15 minutes.”

The test run the county did over the summer with flu shots proved invaluable in helping things go smoothly for the COVID-19 shots. The flu clinic was so popular that more than 700 people got their flu shots in two days—in normal years, that’s how many people are immunized on average over the entire flu season of about five months, says Mueller. The success of that experience helped the county’s public health team learn the best ways to manage traffic flow into and out of the facility, how to predict when demand might be highest and lowest, and how best to communicate with the public not just about the existence of the drive-through clinic, but also to answer any questions they might have about the shot.