GRAFTON, Wis. (NewsNation Now) — Clinicians had to discard about 500 doses of the Moderna vaccine after vials were intentionally removed from refrigeration at Aurora Medical Center in Grafton, Wisconsin.

“Earlier this week, we learned that 57 vials of Moderna vaccine were removed from a pharmacy refrigerator at Aurora Medical Center – Grafton overnight, resulting in more than 500 doses of vaccine being discarded,” the clinic said in a statement to NewsNation.

An internal review initially found it was an inadvertent human error until the individual said they intentionally removed the vaccine from refrigeration.

The individual is no longer employed by Aurora Medical Center.

“We are more than disappointed that this individual’s actions will result in a delay of more than 500 people receiving their vaccine,” the clinic said.

Clinicians were still able to administer some of the vaccines from the vials within the allowable 12-hour post-refrigeration window. Once the vaccine is thawed, it cannot be refrozen.