ProMED-Mail reported on a discovery of vials labeled Smallpox in a Montgomery County, PA vaccine facility operated by Merck on November 17.  Fifteen vials were located in a freezer that was undergoing cleanout.  Five of the vials were labeled “Vaccinia” and the remainder as “Smallpox”. 

The discovery led to an immediate lockdown of the facility.  Following assay showing that all vials contained vaccinia virus and not the variola strain virus capable of causing smallpox, the lockdown was lifted.  Authorities are still investigating the origin of the vials.  Currently only two designated World Health Organization sites hold stocks of variola virus.  In the U.S. the Centers for Disease Control in Atlanta is a repository of presumably to develop diagnostic reagents in the event of bioterrorism.  The second site is the State Research Center for Virology and Biotechnology located in Novosibirsk in the Russian Federation. 

In July 2014, FDA employees discovered six vials containing variola virus during a move from the Bethesda, MD facility.  The FDA had previously received the vials from NIH in 1972 and were stored for 29 years.  There was no evidence that any of the vials were opened and there was no exposure of laboratory workers.

Smallpox could be used as a biological weapon since a high proportion of the world’s population is susceptible to variola virus other than the elderly who were vaccinated as infants and juveniles and military personnel who have received the vaccine.  The discovery demonstrates the risk of laboratory accidents from negligence or deviation from established procedures. Specific gain of function experiments especially if conducted by inexperienced personnel or in facilities inadequately equipped to sequester pathogens represent a serious threat to world health.