BioterrorismFinding a smallpox vaccine for the event of a bioterror attack

Published 6 July 2010

Smallpox is a potentially fatal and highly contagious infectious disease, estimated to have killed between 300 million and 500 million people in the first half of the twentieth century; the world was declared free of smallpox in 1980 — concern about the use of smallpox by bioterrorists spurs new research into vaccines

The National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health (NIH), is funding the research that explores whether a single injection of a high-dose vaccine against smallpox provides better protection against the disease than two lower-dose injections of the vaccine given a month apart.

KSDK reports that smallpox is a potentially fatal and highly contagious infectious disease, estimated to have killed between 300 million and 500 million people in the first half of the twentieth century alone. Vaccinations against smallpox were routinely given in the United States until 1971, and the world was declared free of smallpox in 1980.

Because of continuing concern about biowarfare and bioterrorism throughout the world, the United States government is working to improve its ability to protect its citizens in the event of a possible bioterrorist attack with the smallpox virus,” said Sharon Frey, M.D., principal investigator and professor of infectious diseases at Saint Louis University School of Medicine.

IMVAMUNE, the smallpox vaccine made by Bavarian Nordic and under investigation at SLU, differs from traditional older smallpox vaccines, Frey said.

The vaccine virus contained in IMVAMUNE does not replicate in the body, which minimizes post-vaccination complications such as fever, aches and pain, and fatigue. Additionally, IMVAMUNE is injected into the skin, as opposed to the traditional smallpox vaccines, which had been pricked into the skin by a special needle and typically left a dime-sized scar.

The study will compare two doses of IMVAMUNE — a “standard” dose that is given as two injections a month apart, with a dose that is five times higher and given as a single injection.

The standard dose of IMVAMUNE has been tested in more than 2,400 volunteers and has been shown to be generally safe and well tolerated, Frey said.

While the high-dose vaccine has not yet been tested in people, studies in animals showed the vaccine to be well-tolerated.

The research will be conducted at Saint Louis University’s Center for Vaccine Development and the University of Iowa. A total of ninety volunteers will be enrolled at the two study sites. Half of the study volunteers will be given the high-dose version of IMVAMUNE and half the standard dose. Both groups will receive injections at the first visit and twenty-eight days later.