Health Effects of Anthrax Vaccination in the Canadian Forces

Abstract

The objective of this study was to determine whether anthrax vaccine resulted in adverse health effects in Canadian Forces members 8 months after vaccination. A quasi-experimental, retrospective chart review was undertaken for two groups within the Canadian Forces, one group that received anthrax vaccination and another that did not. Information on symptoms, diagnoses, and injuries for 848 persons for which there were approximately 35,000 chart entries was abstracted from charts over a 4.5-year period and was coded using the International Statistical Classification of Diseases and Related Health Problems, 10th edition. The chart retrieval rate was 84%. The mean number of chart entries per person was higher in the comparison group (43.4) than in the vaccine group (38.2). No statistically significant differences were seen in the percent change before and after vaccination in the number of chart entries for specific diagnoses and symptoms for the vaccine group compared with the comparison group. Visual inspection of the time trend in rates showed no unexplained increases in the rate of diagnosis and symptoms in the vaccine group after vaccination. This study found no evidence that the anthrax vaccination resulted in an increase in adverse health effects in the 8-month period after vaccination.