ST. LOUIS - A potentially safer vaccine to protect against anthrax is moving into a larger-scale clinical trial following a successful pilot study conducted at Saint Louis University School of Medicine and three other sites.
Researchers at Saint Louis University's Center for Vaccine Development and its clinical research organization, SoLUtions, are preparing to conduct a phase II human study of a new investigational anthrax vaccine developed by VaxGen Inc.
"The goal is to develop an anthrax vaccine with better protection, an improved safety profile and a simpler dosing schedule," said Geoffrey J. Gorse, M.D., principal investigator for the study and professor of internal medicine at Saint Louis University.
VaxGen Inc., a California-based biotechnology company, is sponsoring the vaccine development and study through an accelerated program funded by the National Institute of Allergy and Infectious Diseases, a division of the National Institutes of Health.
Dr. Gorse said a total of 480 healthy volunteers at twelve sites around the United States, ages 18 to 55 years old, will be recruited for the study. The SoLUtions clinical research staff of Saint Louis University will provide volunteer recruitment and subject management.
Anthrax, caused by a spore-forming bacteria, is an ancient disease of animals and humans. Domestic sheep, cattle, goats and wild herbivores have been frequent victims of the disease. Those who handle infected animals also are at-risk.
Anthrax may be suitable for use in biological weapons because of the ease of spore production, the stability of the anthrax spores and the ability to aerosolize them. In 2001, five people developed fatal cases of anthrax after inhaling anthrax spores sent through the U.S. mail, spurring the U.S. government to develop an improved anthrax vaccine.
In humans, anthrax infection takes three basic forms: cutaneous, gastrointestinal and inhalational. "The most common form is cutaneous anthrax, accounting for greater than 95 percent of the cases," Gorse said. "In these cases infection occurs through a skin cut or abrasion. If untreated, 10 to 20 percent of cases could be fatal."
Gastrointestinal anthrax, very uncommon in humans, is contracted by the ingestion of meat contaminated with Bacillus anthracis. The course of the disease includes acute gastroenteritis, abdominal pain and bloody diarrhea. Left untreated, gastrointestinal anthrax may have a fatality rate of up to 60 percent.
Gorse said inhalational anthrax is the most fatal form, though rarely encountered. Left untreated, the fatality rate is almost 100 percent for inhalational anthrax.
Although the current anthrax vaccine can prevent anthrax, its dosing schedule - six doses over 18 months - and the need for annual boosters are cumbersome. The vaccine candidate being studied at Saint Louis University is designed to require fewer injections.
Volunteers in the trial will be divided into eight groups of 60. Researchers will be studying eight different formulations of the experimental investigational vaccine. All volunteers will be compensated for participating in the study.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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