The vials were found in a freezer on Monday night and an alert was sent out to the Department of Homeland Security, reports WPVI. The news outlet noted that there are two Merck sites near Philadelphia; however, it said that it cannot confirm where the vials were discovered.
The Centers for Disease Control and Prevention (CDC) said in an email to The Hill that there is “no indication that anyone has been exposed to the small number of frozen vials.”
“The frozen vials labeled ‘Smallpox’ were incidentally discovered by a laboratory worker while cleaning out a freezer in a facility that conducts vaccine research in Pennsylvania. CDC, its Administration partners, and law enforcement are investigating the matter and the vials’ contents appear intact,” the CDC said.
“The laboratory worker who discovered the vials was wearing gloves and a face mask. We will provide further details as they are available,” the CDC added.
Yahoo News reports that the CDC will arrive at the lab on Wednesday to obtain the vials.
According to Yahoo News, smallpox, which is also known scientifically as variola virus, is so deadly that only two labs worldwide are authorized to store samples of it. One is in Russia and the other is at a CDC site in Atlanta.
In 1980, the World Health Organization declared that smallpox had been globally eradicated following joint vaccination efforts across nations.
Prior to widespread vaccination, the highly contagious virus infected about 15 million people every year and killed nearly one-third of them, WPVI noted, adding that the last outbreak in the U.S. was in 1947.
Merck, the Department of Homeland Security and the National Institutes of Health did not immediately respond to request for comment.