CDC Investigating 'Smallpox' Vials Found In Pennsylvania Vaccine Lab

The Centers for Disease Control and Prevention and the FBI have launched an investigation after vials labeled "smallpox" were found in the freezer of a vaccine lab in Pennsylvania.

The vials were discovered by a lab worker at the Merck Upper Gwenydd facility while they were cleaning out the freezer. According to Yahoo! News, there were 15 vials in the freezer. Five of them were labeled "smallpox," and the other ten were labeled "vaccinia."

The vials were immediately secured, and the facility was placed on lockdown.

The CDC said that the vials were intact, and there is no indication that anybody was exposed to the virus.

"The laboratory worker who discovered the vials was wearing gloves and a face mask. There is no indication that anyone has been exposed to the small number of frozen vials. We will provide further details as they are available," a CDC spokesperson told NBC News.

While smallpox was eradicated in the 1970s, scientists have continued to study the virus. Currently, there are only two labs authorized by the World Health Organization to store and research the virus, the Centers for Disease Control and Prevention in Atlanta, Georgia, and the State Research Center of Virology and Biotechnology in Koltsovo, Russia.