A U.S. Health and Human Services review confirmed that 592 of the cases were certainly or probably caused by the anthrax vaccine. They classified 123 of the cases as serious, all due to allergic reactions. There were no fatalities among those cases. The military and the FDA say the anthrax vaccine is safe, with no more side effects than many common vaccines. The Pentagon says more than 1,500 vaccinated lab workers at a research and development center at Maryland's Fort Detrick have been tracked for 20 years, with no unexplained symptoms.
Critics say a long-term study on the effects of the vaccine is needed to make sure it is safe.
A letter signed by 35 members of Congress in May urged Defense Secretary William Cohen to suspend the program until a long-term study was done. The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. ABC News Internet Ventures.