At a House hearing, lawmakers questioned Pentagon officials' assertions that the number of adverse reactions to the shots was small and there was no impact on troop readiness. Military officers and federal health officials have repeatedly said the drug is safe and inoculation is the only known way to prevent rapid deaths in troops who inhale anthrax. He also said there has been no specific study of the efficacy of the licensed vaccine in humans who have inhaled anthrax spores. Such studies have been conducted using guinea pigs, rabbits and monkeys. The only study focusing on humans involved mill workers and others whose skin was exposed by touching infected animals.
Anthrax is a naturally occurring bacteria found in domesticated animals.
But Dr. Sue Bailey, the Defense Department's assistant secretary of health, said it would be unethical to test anthrax spores on humans. Chan said a recent survey of soldiers at the Tripler Army Medical Center in Hawaii indicated women had a higher reaction rate to the vaccine than men. Twice the number of women reported they missed one or more duty shifts after a shot, and women were more than twice as likely to report fever, chills or general malaise. The FDA specified that troops are to have six shots with an annual booster to ensure they are properly inoculated. But Chan said no studies had determined the optimum number of shots required.