Vials labeled “smallpox” found at a vaccine research facility in Pennsylvania, CDC says

“There is no indication that anyone was exposed to the small number of frozen vials,” the CDC said in a statement emailed to CNN.

“The frozen vials labeled ‘Smallpox’ were further discovered by a lab worker while cleaning a freezer at a facility that conducts vaccine research in Pennsylvania. CDC, its Administrative Partners, and police are investigating the matter and the contents of the vials appear intact.”, The CDC added .

“The worker who discovered the vials wore gloves and a face mask. We will provide additional details when they become available.”

Smallpox, also known as smallpox, was declared extinct in 1980 by the World Health Organization after coordinated global vaccination. Prior to that, the virus, which spreads easily from person to person, infected 15 million people a year and killed about 30% of them. The last known outbreak in the United States was in 1947.

In 2014, employees of the National Institutes of Health found six vials of smallpox in an unused warehouse when they packed a lab at the NIH’s Bethesda, Maryland campus to move it. Two of the vials contained a viable virus. The CDC said at the time that there was no evidence that anyone had been exposed to the contents of any of the vials.

Governments quarreled over whether to keep samples of the virus or destroy all known copies. Most routine vaccination stopped in 1972 but military personnel and some researchers are still vaccinated.

The CDC recommends that people get smallpox every 3-5 years to stay protected although at least one study has indicated that vaccinated people may have at least some immunity for life.