Coronavirus updates: US reports nearly 300,000 new cases in all-time high

A former employee at Aurora Medical Center in Grafton, Wisconsin, has been arrested for "intentionally" removing Moderna vaccines from refrigeration, authorities said Thursday.

Over 500 doses were spoiled, and 57 people received less-effective doses of the vaccine, Dr. Jeff Bahr, president of Aurora Health Care Medical Group, said Thursday.

On Dec. 26, a pharmacy technician found 57 vials of the vaccine, equivalent to 570 doses, outside the refrigerator in which those vials were meant to be stored. The vaccine vials were returned to the refrigerator and the technician reported the incident to superiors.

The “pharmacist responsible for removing the vials” initially maintained that the “incident was an inadvertent error that occurred while the individual was accessing other items from the same refrigerator," Bahr said. However, an investigation revealed that the employee “admitted yesterday to intentionally removing the vaccine from refrigeration,” Bahr said.

The individual also “admitted to removing and then returning the vaccine to the refrigerator overnight, on the evening of Dec. 24 into Dec. 25,” Bahr said. No vaccinations were administered on either day, he said.

The Moderna vaccine must be kept refrigerated between 36 and 46 degrees Fahrenheit, and based on available information, the hospital initially determined that the vaccine was still able to be administered given the allowable 12-hour post-refrigeration window. After 57 doses of the vaccine were administered on Dec. 26, the remainder of that vaccine was discarded, when it was deemed ineffective, following an internal review.

The recipients of those vaccines were subsequently notified, and Bahr said that at this time, that although the vaccines are considered "less effective or ineffective," there is no evidence that the vaccinations pose any harm to them.

Aurora Health has been in communication with Moderna, and the biotech company has assured the health company that there are no safety concerns pertaining to administering a vaccine that may have been out of refrigeration for too long.

The health care company will continue to work with Moderna and the Food and Drug Administration to identify a strategy for future vaccinations for those 57 people.

"It's become clear that this was a situation involving a bad actor, as opposed to a bad process," Bahr said.

The value of the spoiled doses was estimated to be between $8,000 and $11,000, the Grafton Police Department said.

The former employee was arrested Thursday on recommended charges of first-degree recklessly endangering safety, adulterating a prescription drug and criminal damage to property -- all felonies. His name is being withheld at this time, and he is currently being held in the Ozaukee County jail, authorities said.

The FBI and the FDA are also investigating.

ABC News' Arielle Mitropoulos contributed to this report.

Sen. David Perdue, who is seeking reelection in the Georgia runoff on Jan. 5, will quarantine after Perdue was told Thursday morning that he was in "close contact with someone on the campaign who tested positive for COVID-19,” his campaign said in a statement.

Both Perdue and his wife, Bonnie, tested negative for the coronavirus Thursday and have been tested regularly throughout the campaign, according to the statement.

Perdue's wife will also quarantine, the statement said.

ABC News' Quinn Scanlan contributed to this report.

The World Health Organization has approved the Pfizer/BioNTech vaccine for "Emergency Use Listing," which it says “opens the door for countries to expedite their own regulatory approval processes to import and administer the vaccine.”

Emergency Use Listing also lets UNICEF and the Pan-American Health Organization "procure the vaccine for distribution to countries in need,” the WHO said.

“This is a very positive step towards ensuring global access to COVID-19 vaccines. But I want to emphasize the need for an even greater global effort to achieve enough vaccine supply to meet the needs of priority populations everywhere,” Dr Mariângela Simão, WHO assistant director-general for Access to Medicines and Health Products, said in a statement. “WHO and our partners are working night and day to evaluate other vaccines that have reached safety and efficacy standards. We encourage even more developers to come forward for review and assessment.”

ABC News' Kirit Radia contributed to this report.

In Yakima, Washington, 145 employees at a Costco have tested positive for COVID-19, the Yakima Health District said.

The outbreak was first announced on Christmas Eve with 68 staff members testing positive. Once testing was expanded to all employees, the number grew to 145.

“After reviewing the number of cases, and the timeline in which they were identified, there is evidence to show that this sharp increase in cases mimics the type of activity that happens after some sort of super- spreader event where multiple people are infected at the same time,” the health district said.

“For Costco specifically, site-wide testing was recommended given the large number of infected employees. When site-wide testing is recommended, the organization provides testing to all employees, regardless of whether they were identified as an initial close contact to a positive COVID-19 case or not,” the health district continued. “Costco will continue to provide on-going site-wide testing for their employees moving forward to monitor the outbreak.”

ABC News' Matt Fuhrman contributed to this report.