whether they had received the active vaccine or placebo; the article does not state whether the investigators were also blinded.

The report of the study does not always clearly distinguish the results in the three mills for the 480 subjects who completed the vaccination series from the 81 subjects who did not complete the series. Neither does it clearly distinguish the results for the 480 subjects in the three mills who completed the series from results for the subjects from the largest mill who had been randomized, received the initial injections, and were partially evaluated prior to the mill’s withdrawal from the study.

The participants were examined 24 and 48 hours following each vaccination to assess both local and systemic reactions to the vaccine. There was no report of subsequent active or passive surveillance for possible adverse effects beyond 48 hours after each vaccination (there was further monitoring for the vaccine’s efficacy, however). The typical reaction is described as a ring of erythema (1–2 cm in diameter) at the injection site, with local tenderness that lasted 24–48 hours. Some subjects (a number was not given) reported more extensive edema, erythema (>5 cm in diameter), pruritus, induration, or small painless nodules at the injection site (lasting up to several weeks). Twenty-one persons had moderate local edema that lasted up to 48 hours. Three individuals had edema extending from the deltoid to the mid-forearm (in one case, to the wrist) that dissipated within 5 days. The only systemic reactions were reported in two individuals (0.9% of the actively vaccinated subjects), who experienced “malaise” lasting 24 hours following vaccination. The study notes that three individuals who received the placebo (0.1% alum) had mild reactions.

The committee located only one published series of studies that discussed long-term follow-up of individuals who received multiple vaccinations, including the anthrax vaccine, due to the nature of their employment. A group of employees at Fort Detrick, Maryland, were followed for an average of 25 years to investigate the potential subclinical effects of intensive vaccination.³ The participants underwent physical examinations and/or laboratory testing in 1956 (n=93), 1962 (n=76), and 1971 (n=77) (Peeler et al., 1958, 1965; White et al., 1974).

No clinical sequelae attributable to intense long-term immunization could be identified in this cohort. None of the subjects suffered unexplained clinical symptoms requiring them to take sick leave that could be attributed to the vaccination program. There was some evidence of a chronic inflammatory response, as characterized by certain laboratory test abnormalities: elevated levels of hexosamine, an acute-phase reactant, and polyclonal

Front Matter (R1-R5)

An Assessment of the Safety of the Anthrax Vaccine: Letter Report (1-8)