( In the event of a smallpox outbreak in ...)Smallpox outbreak: How long would it take for vaccines to protect people? Would it work?

A new national study led by Saint Louis University School of Medicine will attempt to answer this question.

General routine vaccinations for smallpox were stopped in the United States in 1971, and the world was declared free of smallpox in 1980. But because of the recent concern about biowarfare and bioterrorism throughout the world, the U.S. government is making efforts to improve its ability to protect its citizens in the event of a bioterrorist attack involving the smallpox virus (Variola major virus).

This study at Saint Louis University will look at the ability of an investigational vaccine made by Bavarian Nordic to stimulate the immune system against smallpox.

"Vaccines prevent disease by giving the body a jump-start at recognizing the infecting virus or bacteria," said Sharon Frey, M.D., the principal investigator for the study at Saint Louis University. "After successful vaccination, the body experiences a quicker fighting response to the infection, which lessens or completely avoids the symptoms of illness."

Unlike some other diseases, getting vaccinated following exposure to smallpox could provide protective effects. For example, for the flu vaccine to work, people need to get vaccinated before being exposed to influenza. The currently licensed smallpox vaccine, however, provides benefits post-exposure, and may be useful in further preventing the spread of the disease.

"If there were a release of the smallpox virus, we would vaccinate people immediately after the release," Frey said. "We'd move in and vaccinate people to prevent the spread."

Frey said this research compares the ability of a new investigational smallpox vaccine called IMVAMUNE® to produce a strong immune response against smallpox d
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Source:Saint Louis University