The discovery of old vials of smallpox in a storeroom at the National Institutes Of Health this month has prompted an FBI investigation.
Smallpox is a highly contagious and deadly disease that's been wiped out since 1980.
The vials were first put in a containment lab.
Law enforcement then moved them to the CDC's high-containment facility in Atlanta.
The CDC says there's no indication that any of the vials were opened or that workers were exposed to the virus.
Tests were done to confirm that the smallpox virus DNA was present.
There will more tests to see if the virus could grow in tissue culture and then it will be destroyed.
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