Results show that no studies have been done to determine the optimum number of doses of the anthrax vaccine. Although annual boosters are given the need for a six-shot regimen and annual booster shots have not been evaluated. The long-term safety of the licensed vaccine has not been studied. The Department of Defense (DOD) is designing studies to examine the vaccine’s long-term effects. Data on the prevalence and duration of short-term reactions to the vaccine are limited. It is suggested that women experience a higher rate of adverse reactions than do men. A higher proportion of women reported both local and systemic reactions to the vaccine than their male counterparts. More than twice the proportion of women reported that they missed one or more duty shifts after their vaccinations than did males. The system for collecting data on adverse events associated with the vaccine relies on vaccine recipients or their health care providers to report adverse events. Such systems may not accurately reflect the incidence of events due to underreporting. A study on the efficacy of the earlier vaccine concluded that it provided protection to humans against anthrax penetrating the skin but did not provide information to determine its effectiveness against inhalation anthrax. DOD plans to develop a second generation vaccine and will need to address whether strains of deliberately engineered or naturally occurring anthrax can overcome the protective immunity of such a vaccine. The inspections of the vaccine production facility found two deficiencies in two categories: those that might affect only one or a limited number of batches of vaccine that were produced and those that could compromise the safety and efficacy of any or all batches. The facility was shut down in nearly 1998. The anthrax vaccine is not intended to be administered to children, pregnant women, or lactating women. No studies have been conducted on the vaccine’s effects on these groups. 3 tables, 6 footnotes