SAN DIEGO (KUSI) – The delayed arrival of an expected shipment of Moderna COVID-19 vaccines created a shortage in the county Friday, forcing some vaccination sites to dramatically slow the pace of inoculations or reschedule appointment altogether. The shipment is now expected to arrive Tuesday. County officials did not immediately return a call as to how many doses are expected in the shipment. The interruption will affect the region’s largest vaccination site, the UC San Diego Health Petco Park Super Station, with no vaccinations taking place on Sunday, Monday and Tuesday. Petco appointments will be automatically rescheduled through UCSD MyChart.