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

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.

Hard-hit California reported 428 new deaths on Thursday, following Wednesday’s daily record high of 432 fatalities.

The Golden State’s death toll is now over 25,000.

ABC News' Matt Fuhrman contributed to this report.

Forty-two people in West Virginia received the Regeneron monoclonal antibody treatment instead of the Moderna vaccine on Wednesday at a vaccination clinic hosted by staff at the Boone County Health Department, the West Virginia National Guard confirmed to ABC News.

Medical experts with the Joint Interagency Task Force do not believe there is any risk of harm to these 42 individuals. Everyone who received the monoclonal antibody has been contacted, or is in the process of being contacted, according to the West Virginia National Guard.

“The moment that we were notified of what happened, we acted right away to correct it, and we immediately reviewed and strengthened our protocols to enhance our distribution process to prevent this from happening again,” Maj. Gen. James Hoyer, Adjutant General of the West Virginia National Guard, said in a statement.

The Regeneron treatment was administered intramuscularly, like a traditional vaccination, according to the West Virginia National Guard. The Regeneron treatment, which was given FDA emergency authorization in November, is normally given as an intravenous infusion, not an intramuscular injection.

The recommendation from the Centers for Disease Control and Prevention is that for those who receive antibody treatments, "vaccination should be deferred for at least 90 days, as a precautionary measure until additional information becomes available, to avoid interference of the antibody treatment with vaccine-induced immune responses."

A West Virginia National Guard official told ABC News that "there are no concerns that this will set individuals back 90 days" and that "all 42 individuals are being offered the vaccine today."

ABC News' Arielle Mitropoulos contributed to this report.

U.S. Surgeon General Jerome Adams tweeted Thursday morning that his wife had been admitted to a hospital because of complications with her cancer treatment. He said he wasn’t allowed to visit her because of COVID-19-related restrictions.

Adams’ wife, Lacey Adams, was first diagnosed with metastatic melanoma in 2018.

“I’m hoping she doesn’t have to spend New Year’s in a hallway because the beds are full,” Adams tweeted.

ABC News’ Ben Gittleson and Tom Dunlavey contributed to this report.