Smallpox Vaccine, Dried, Calf Lymph Type, trade name Dryvax, is the only smallpox vaccine currently licensed in the U.S. The manufacturer of this vaccine is Wyeth Laboratories, Inc. Dryvax helps the body develop immunity to smallpox. Dryvax is a live-virus preparation of vaccinia virus prepared from calf lymph. The calf lymph is purified, concentrated, and dried by a process called lyophilization. Vaccinia is a "pox" type virus that is related to the virus that causes smallpox. The vaccinia virus can protect against smallpox, and unlike smallpox, vaccinia rarely causes serious disease in previously healthy people. The vaccine cannot give you smallpox. Dryvax was first approved in 1931. The existing doses of Dryvax vaccine were manufactured in the 1970s and early 1980s and stored frozen at -20°C. Licensed vaccine lots have to meet specific criteria in order to be distributed, including current testing to demonstrate the potency (strength) of the vaccine and the container-closure integrity of the vaccine vials. In October 2002, FDA approved a new 100-dose kit for Dryvax, which includes a new supply of diluent (the liquid mixed with the dried vaccine before it is administered) and bifurcated (double pointed) needles for vaccine administration. Prior to this approval, Dryvax had been available for use only under an investigational new drug application (IND). With this approval, Dryvax can again be distributed and used as an approved product. All supplies of Dryvax for civilian use are under the control of the Centers for Disease Control and Prevention, in conjunction with the Department of Health and Human Services. | 
