The history of pandemics 03:58. Frozen vials labeled "Smallpox" that were discovered in a freezer at a vaccine research facility in Pennsylvania "contain no trace of virus known to cause smallpox ...

Vials with “smallpox” labels found at a Pennsylvania lab contain the virus used in the vaccine and not the virus that causes the disease, officials said.

The vials were found earlier this week when a lab worker was cleaning out a freezer at the Merck facility located in North Wales, Pa. 24/7 Live Philadelphia Pennsylvania New Jersey Delaware.