Summary: Some ailing Gulf War veterans believe that the military's anthrax vaccine is the cause of their unexplained health problems. Concerns about the safety and the efficacy of the vaccine have also been fueled by the Food and Drug Administration's discovery of problems at the facility manufacturing the vaccine. Studies of both the original anthrax vaccine (developed in the 1950s and first produced on a large scale by Merck) and a later version that was eventually licensed and given to U.S. troops (produced by the Michigan Department of Public Health using a different process) did not question the safety of the vaccine. However, depending on the type of monitoring system used, recorded reactions to the vaccine varied; short-term local or systemic reaction rates were higher under active monitoring systems than under passive ones. The vaccine's long-term safety has yet to be studied. A study done on the original vaccine concluded that it protected humans against Anthrax exposure through the skin. In the 1980s, DOD began testing the licensed vaccine in animals to see how well it protected against anthrax that was inhaled. These studies found that the licensed vaccine protected against some but not all strains of anthrax. Animal immunity, however, does not necessarily correspond to human immunity because the relationship between the level of immunity and protection rates has not been demonstrated. The Defense Department plans further research in this area. After FDA inspections of the facility manufacturing the vaccine uncovered numerous problems, the agency sent warning letters, including one in March 1997 announcing FDA's intention to revoke the facility's license. The facility closed its plant the following year and it is now being renovated. DOD is conducting supplemental testing of the lots of vaccine in its current inventory before distributing it.
