The effectiveness and safety of vaccines against human anthrax: a systematic review.

We report on the results of a systematic review of existing controlled clinical trials undertaken to assess the effectiveness and safety of vaccines against human anthrax in relation to disease incidence and side-effects. Two articles retrieved by electronic and hand search fulfilling some of the inclusion criteria underwent a quality assessment by a group of reviewers. Data synthesized from the two trials showed that estimates of overall effectiveness and safety favour treatment (overall odds ratio 0.16; 95% confidence interval 0.07-0.34). The route of inoculation appears to make little difference to the effectiveness of the vaccines; however, one study shows that the incidence and severity of side-effects are significantly higher with the killed vaccine than with the alum-based placebo (overall odds ratio 0.16; 95% confidence interval 2.38-27.17).