Infectious diseases researchers Philip Felgner (pictured) and Huw Davies with the University of California, Irvine Department of Medicine have shown the effectiveness of a potential alternative to the existing smallpox vaccine. They found that the modified vaccinia virus Ankara (MVA) produced the same antiviral response in human and animal studies as the current smallpox vaccine, Dryvax. The study is part of a national effort to develop a replacement for the current biodefense stockpile of Dryvax vaccine, which causes serious complications in some people. Smallpox has been eradicated worldwide since 1980, but it has been identified as a potential bioterrorism agent. Study results appear in the Journal of Virology.