Health officials with Advocate Aurora Health from Milwaukee, Wisconsin, announced Monday that dozens of Moderna COVID-19 vaccine vials were taken and accidentally left out of a freezer over the weekend.
"We learned that about 50 vials of Moderna vaccine were inadvertently removed from a pharmacy refrigerator overnight," an Advocate Aurora Health spokesperson told local outlet TMJ4 Milwaukee.
A total of 50 full vials would account for 500 first-round doses of the vaccine.
Health officials noted, however, that some doses were properly administered to individuals prior to refrigeration and removal in question.
"While some of the vaccine was administered to team members on Dec. 26 within the approved 12-hour post-refrigeration window, unfortunately, most of it had to be discarded due to the temperature storage requirements necessary to maintain its viability," the spokesperson said.
"We are clearly disappointed and regret this happened."
The CDC website details that the Moderna vaccine "may be stored in a freezer between -25°C and -15°C (-13°F and 5°F)." The Pfizer-BioNTech vaccine can be stored "in an ultra-cold freezer between -80⁰C and -60⁰C (-112⁰F and -76⁰F)."
"The vaccination program at Aurora Grafton continues uninterrupted because we were able to redirect vaccine supply from other Aurora sites, and we expect additional shipments in the near future," another spokesperson for the company told The Hill, noting that there were no Pfizer-BioNTech vaccines available at their hospital.
The US Food and Drug Administration approved the Pfizer-BioNTech and Moderna vaccines for emergency use in individuals 18 years or older on December 11 and December 18, respectively.
Both Friday approvals for the vaccine were followed by a Monday rollout of the first doses of the two-round vaccination.