A lab worker at a Merck facility outside Philadelphia found 15 “questionable vials” labeled “smallpox” and “vaccinia” while cleaning out a freezer earlier this week, raising harrowing security concerns.
The FBI and the Centers for Disease Control and Prevention are investigating the discovery, which involves a disease that is believed to have killed more than 300 million people since the dawn of the 20th century.
The Pennsylvania facility, which does vaccine research, is no longer on lockdown. The lab worker had on gloves and a face mask when they found the vials, the CDC said.
“There is no indication that anyone has been exposed to the small number of frozen vials,” a CDC spokesperson told Yahoo News, adding that their “contents appear intact”.
Officially, smallpox can only be stored at two places in the world, located in Atlanta and Russia. Other unauthorized samples should have been transferred or destroyed, the Philadelphia Inquirer reported, though some have popped up elsewhere in recent years.
The disease killed roughly three out of 10 people who contracted it, the CDC says, an unimaginable loss of life. But by the late 20th century, it had been defeated globally, a feat many consider “the biggest achievement in international public health”.
Smallpox remains one of only two officially eradicated diseases, according to the American Society for Microbiology.
Richard Ebright, a professor of chemistry and chemical biology at Rutgers University, suggested to the Inquirer that the vials in Pennsylvania represented a security threat. Someone with bioterrorism plans could have found them and used them.
But people should not be afraid that the vials will cause an outbreak, and even the lab worker who discovered them should be safe, he said.
“For the general public there is no basis for being worried, even a small amount,” Ebright said.