The potential threat of a biological attack has spurred efforts to develop
a safer smallpox vaccine, and now researchers may have found a promising candidate.
While the currently licensed vaccine—live vaccinia virus—can
cause serious adverse effects in immunocompromised individuals, an attenuated
strain has been recently shown to be both safe and effective in two animal
models. A safer smallpox vaccine would be a welcome advance for the millions
of individuals in the United States who could be harmed if they took the current
Hampton T. New Smallpox Vaccine Shows Promise. JAMA. 2004;291(15):1825. doi:10.1001/jama.291.15.1825