ST. LOUIS — More than 7,700 doses of vaccine were left over after mass vaccination events across Missouri last week, fueling frustrations rural counties haven't been able to find enough people to use them while urban residents are desperate for a dose.

Records from the Missouri Department of Public Safety show the remaining doses were usually transferred to another local provider or held by the health department for later use, the St. Louis Post-Dispatch reported.

Over the course of those clinics, 152 doses were thrown away, including Putnam County where 143 doses spoiled. In some cases, the spoilage resulted from dislodged needles or duplicate appointments and others when residents didn't show up for their slots.

In Putnam County, 1,488 doses remained after a vaccination event last weekend. In Bollinger County, only about half of the available doses were used at an event Feb. 24, and the leftovers were sent elsewhere.

In Lewis County, a mass vaccination event concluded with hundreds of extra doses. That left enough vaccine for a follow-up day catering largely to people from far outside the area.

State agencies say they are adjusting. The state will transition mass vaccination teams to hold more large-scale events in the Kansas City and St. Louis areas.