SAN DIEGO — A delayed vaccine shipment is throwing another wrench in San Diego’s vaccine rollout, with a supply shortfall forcing the county to pause some appointments.

The County of San Diego announced the shortage Friday and said it was caused by a delayed Moderna shipment. Originally expected sooner, it will now arrive Tuesday, officials said.

That means the “super station” at Petco Park will not be able to offer vaccinations on Sunday, Monday or Tuesday, and residents who already had appointments will be automatically rescheduled through UC San Diego Health’s MyChart program.

“The South County Super Station has supplies sufficient to get it through Monday, as does the East County Super Station,” the county’s statement said.

Smaller sites around the region, called PODs, and the super station at Cal State San Marcos in North County have enough supplies to meet their existing second-dose appointments, and will still provide some limited first shots.

“They’re going to get the highest priority and they will be rescheduled, and they should be able to catch them all up middle of next week,” Supervisor Nathan Fletcher said of those needing a second dose. “Moderna was the shipment that didn’t arrive, so locations that are administering Pfizer ought to be able to continue on as planned.”

The county said for those who may experience a delay in second doses, the Centers For Disease Control and Prevention has advised that people can wait up to 42 days between doses and still achieve maximum immunity. More information about getting the COVID-19 vaccine in San Diego available online.

Short supply has been San Diego’s primary concern during the rollout, as the region has been lauded for setting up the infrastructure to distribute far more shots — if only the doses were available.

“We’re not the only place that’s experiencing this,” Fletcher said. “Other counties are having to pause their operations at super stations because of a similar lack of supply.”

Fletcher said this week he expects a significant rise in supply around early March. He told reporters the county prefers to set up the sites ahead of time so they can act quickly when shipments arrive, rather than wait for guaranteed doses to establish infrastructure.

“We could administer significantly more vaccines on a daily basis with the networks of sites that we built out, along with what other providers can do in the region,” Fletcher said Thursday in a news conference. “We just need the supply to kick up.”