The six long-lost vials of smallpox found this month at a government lab were only a small part of a cache of forgotten biological samples, officials announced Wednesday.
Smallpox was discovered among more than 300 vials in a cold-storage area in a Food and Drug Administration lab on July 1. Among the labels on those vials: dengue, influenza and Q fever. The discovery has raised serious questions about what else may be hiding in labs across the country.
FDA officials said Wednesday that the agency planned to sweep all its common cold-storage facilities, including at its main campus in White Oak, Md., and satellite locations around the country.
"The fact that these materials were not discovered until now is unacceptable," said Karen Midthun, director of the FDA's Center for Biologics Evaluation and Research.
Twelve boxes containing a total of 327 vials were found July 1 in an FDA lab area on the National Institutes of Health campus in Bethesda, Md.
"All of the items labeled as infectious agents found in the collection of samples were stored in glass, heat-sealed vials that were well-packed, intact and free of any leakage, and there is no evidence that anyone was exposed," the FDA said in a statement.
The boxes sat together in the corner of a walk-in cold-storage area, in an area that wasn't frequently accessed, FDA officials told reporters Wednesday afternoon. The samples inside were probably put there between 1946 and 1964, before the FDA occupied the lab area, the agency said.
The six vials labeled "variola," or smallpox virus, were turned over to the federal Centers for Disease Control and Prevention, as were 10 vials whose labels were not clear, the FDA said. Only two labs — one at the CDC in Atlanta and another near Novosibirsk, Russia — are "designated repositories" for smallpox. All other labs in the world were required to destroy their smallpox strains or transfer them to the two labs, according to an international agreement reached in 1979.
Thirty-two of the vials in the cache, labeled as normal tissue or as smallpox-vaccine virus, were destroyed, and the rest of the vials were transferred to the Department of Homeland Security for safeguarding, the FDA said.
"We take this matter very seriously, and we are working to ensure this does not happen again," Midthun told reporters in a conference call. FDA officials said there would be an investigation but would not estimate when it would be complete.
The most common type of smallpox is serious, contagious and frequently fatal, with about 30% of cases resulting in death, according to the CDC. The disease was declared eradicated in 1980 after a worldwide vaccination program.
Smallpox was the most severe of the biological agents found in the cache, an FDA spokeswoman told the Los Angeles Times in an email. "There were no other Tier 1 agents," she wrote.
The FDA defines Tier 1 agents as those that "present the greatest risk of deliberate misuse with significant potential for mass casualties or devastating effect to the economy, critical infrastructure or public confidence and pose a severe threat to public health and safety."