From Fox News;
RICHMOND, Va. – An outbreak of smallpox was the furthest thing from historian Dr. Paul Levengood's mind when his staff at the Virginia Historical Society put together an exhibit of "bizarre bits" that were added to the society's collection since its founding in 1831, The Wall Street Journal reported Thursday.
There was Confederate president Jefferson Davis's cigar, confiscated by Union troops. There was a fungus carving of Robert E. Lee on his horse, Traveller, and a wreath made of human hair.
Then someone mentioned a letter, handwritten and dated 1876, with what appeared to be a smallpox scab pinned inside -- light brown, about the size of a pencil eraser and crumbling.
The scab got the attention of the Centers for Disease Control and Prevention (CDC), home to one of the world's two known caches of live smallpox viruses.
Alerted by a government scientist in Maryland who was concerned that the scab might transmit infection, the agency dispatched two CDC representatives to Richmond. They donned disposable surgical gowns and gloves, lifted the scab from a display case, sealed it in bio-bags inside a red cooler and whisked it back to a high-security lab deep within the CDC's Atlanta headquarters.
Scabs -- pieces of desiccated skin that contain white blood cells, viruses and other material --were used in the 19th century to vaccinate people against smallpox. They were inserted into small breaks in the skin, prompting the body to build an immune response.
The scab the CDC retrieved from Virginia was mailed from a son to his father. "Dear Pa ... the piece I inclose is perfectly fresh and was taken from an infant's arm yesterday," read the letter.
"Dr. Harris says the inclosed scab will vaccinate 12 persons, but if you want more, you must send for it. I will pin this to the letter so that you cannot lose it as you did before."
Museum officials said they were not worried about infection because a medical historian told them years ago that old scabs degrade. "Our strong assumption was that it was not a danger," Levengood said.
When the CDC retrieved the scab, they assured historical society staff that the chances of infection appeared low. Staff locked it in the trunk of their car and drove straight to Atlanta, a nine-hour trip.
Clad in pressurized moon suits in the high-security, BSL-4 lab, CDC microbiologists determined within a few hours that the scab contained virus from the smallpox vaccine but did not contain the deadly disease virus itself. They have since moved the scab, which was irradiated, to a medium-security lab.