Saint Louis University said Monday it will lead a national study of a new vaccine for smallpox, once one of the world's most feared diseases and now considered a threat to re-emerge as a biological weapon.
The university's Center for Vaccine Development and six other U.S. centers will examine how quickly the test vaccine stimulates an immune response and whether it would be as effective as a vaccine used in previous global smallpox eradication efforts.
The study is sponsored by the National Institutes of Health and the test vaccine's manufacturer, the Danish firm Bavarian Nordic.
Smallpox was eradicated globally in 1980 as the result of a World Health Organization campaign. But concerns that stored smallpox virus could be used in a bioterrorist attack has prompted questions about how quickly a vaccine could start protecting exposed citizens.
"If there was a release of smallpox today, and we vaccinated today, how rapid would the immune response have to be in order to prevent the person from developing the disease?" asked Dr. Sharon Frey, the study's principal investigator.
"Historically, it's been three days."
The test smallpox vaccine, Imvamune, is expected to have fewer side effects than Dryvax, a vaccine used for years to protect against smallpox, Frey said.
Imvamune is a much weaker form of the virus than Dryvax.
"The main point of the study is to see if it takes less time to make antibodies against Imvamune as compared to Dryvax and will the antibody response be at least as good," Frey said.
The test vaccine will be studied alone, and in combination with Dryvax for comparison.
Saint Louis University's Center for Vaccine Development has conducted several smallpox vaccine studies in recent years. Notably, in 2001, the center studied the potency of Dryvax left over from 1980 when it was last produced and used. The study was prompted by bioterrorism fears of the 1990s, and predated the Sept. 11, 2001, terrorist attacks.
The seven study sites will enroll 215 people, including 30 in St. Louis.
The last case of smallpox in the U.S. was in 1949; the last case in the world was in 1977 in Somalia.
Bavarian Nordic has its headquarters in Denmark with operations in Germany, Singapore and the U.S.
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