AP News, May 1st, 2007
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 bioweapon.
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 Danish manufacturer, 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 was believed that if people were vaccinated within three to four days of exposure they could be protected from the disease," she said.
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 weakened form of the vaccinia virus, used to protect against smallpox.
"The main point of the study is to see if it takes less time to make antibodies against Imvamune as compared to Dryvax and if the antibody response will be at least as good," Frey said.
The test vaccine will be studied alone, and in combination with Dryvax.
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.
Study participants must have been born after 1971, the year routine smallpox vaccinations using Dryvax stopped in the U.S. They will be studied for their antibody response.
The last case of smallpox in the U.S. was 1949; the last case in the world was 1977 in Somalia.
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On the Net:
National Institutes of Health: http://www.nih.gov/
Saint Louis University Center for Vaccine Development: http://medschool.slu.edu/vaccine/
Bavarian Nordic: http://www.bavarian-nordic.com/
