[Delayed hypersensitivity in man after booster anthrax vaccination].

The purpose of this study was to ascertain the need for boosters after administration of STI anthrax vaccine. Postvaccination dynamics was assessed by observing the intradermic reaction of anthraxine. The study included 138 subjects vaccinated 15 months earlier by subcutaneous injection or 128 subjects vaccinated 24 months earlier by aerosol inhalation. Subjects were tested using the anthraxine test in separate groups on D2, D7, D15, D90, D180, and D365 after administration of the booster via the same route as the primary vaccination. Immediately before administration of the booster residual positive skin reactions were observed in 14.3% of subjects in the subcutaneous vaccination group and 8.3% of subjects in the aerosol vaccination group. After the booster, the proportion of subjects with positive skin reactions increased rapidly. The proportion of positive skin reactions after the booster was not statistically different from the proportion after the primary vaccination. This study provides scientific evidence supporting the need for boosters after anthrax vaccination and demonstrated an absence of sensitization by anthraxine during tests to evaluate response kinetics in subjects after primary vaccination. Several questions remain to be answered concerning the optical booster dose, the most effective timing, and the value of acellular vaccines.