1. Omitting one dose, and injecting the vaccine deeper into muscle was widely reported to reduce adverse effects. But only brief local reactions at the skin are reduced, as one might expect with a deeper shot. The occurrence of the more consequential systemic adverse events was "not significantly influence[d]" by route of administration.
2. Women continued to have signficantly higher local and systemic event rates (approximately double the systemic adverse event rate of men) as has been reported in 4 previous studies since 2001.
3. Immunogenicity was assessed by using a measure relatively unique to anthrax vaccine: the geometric mean concentration and geometric mean titre of anti-PA antibody, as well as a fourfold rise in titre. In several animal models, antibody titres have not corresponded with survival rates following anthrax exposure. There is still no direct measure of efficacy in humans for this vaccine, in any published literature or manufacturer submission, although required by FDA regulations. (The FDA's Animal Rule, which includes ways to use substitute animal data for this requirement, has not been used to license this vaccine.)
4. There were 229 serious adverse events reports (including 7 deaths) filed with VAERS during the study, and a number of people were withdrawn from the study at the direction of the principal investigator due to adverse events. Yet the Data Safety Monitoring Board rated only seven subjects' adverse events as possibly related to the vaccine. The problem with this is that there is still no standard to tell us the kinds of reaction caused by anthrax vaccine; the package insert fails to provide this information, and one goal of this study originally was to learn about the reactions by comparing the vaccinated and placebo groups. That has not been done.
5. Despite the fact that this report provides no meaningful data to suggest EBS' anthrax vaccine is either safe or effective, the study is being used by CDC to ask its Advisory Committee on Immunization Practices to make a new recommendation for anthrax vaccine use in civilian first responders at its next meeting on October 22, 2008.