A hospital in California suspects that an inflatable Christmas tree costume may be behind a massive COVID-19 outbreak that has infected at least 44 employees, The San Francisco Chronicle reports

A Kaiser Permanente San Jose Medical Center employee briefly wore the air-powered costume in the emergency room on Christmas Day to "lift the spirits" of fellow co-workers, but may have unknowingly spread the virus throughout the facility. "Any exposure, if it occurred, would have been completely innocent, and quite accidental, as the individual had no COVID symptoms and only sought to lift the spirits of those around them during what is a very stressful time," the hospital said in a statement. 

"If anything, this should serve as a very real reminder that the virus is widespread, and often without symptoms, and we must all be vigilant," the statement continued. The emergency room has since undergone a deep cleaning, and all employees who have tested positive between Dec. 27 and New Year's Day are being required to isolate. Kaiser Permanente San Jose is still conducting contact tracing to determine who else may have been exposed. 

One ER employee told NBC Bay Area that they believe staff might have been exposed due to respiratory treatments being conducted "inside a room that they’re not supposed to."

While the hospital had administered the COVID-19 vaccine to some emergency room workers prior to Christmas Day, the first dose doesn't reach its full potential until the second shot is given. Even then, none of the approved vaccines are 100 percent effective against preventing someone from catching the virus. It may go without saying, but air-powered costumes have been banned from the Kaiser Permanente San Jose emergency room. 

California has the most coronavirus cases in the United States with 2.4 million reported. Over 26,000 people in the state have died from the virus.