Dryvax — produced by scraping virus off the skin of infected calves — is being replaced in federal vaccine stockpiles by a more modern product manufactured in laboratories.
Dryvax was unusually dangerous for a vaccine, blamed in recent years for triggering heart attacks and aDryvax was created in the late 1800s, by the company that became in some patients. . was a primary U.S. manufacturer of smallpox vaccine by the mid-1940s, and was the only company left making it by the early 1960s, said Dr. D.A. Henderson, a vaccine expert who played a key role in international .