The authors' research was a welcome start.1 However, many immune disorders take time to develop. If such disorders were related to vaccinations, symptoms might not develop for many months after the vaccinations; yet the authors limited their time frame to less than 18 weeks. Some research that has suggested a relationship between anthrax vaccination and declines in subjective health reports has involved follow-up periods of several years.2 Furthermore, there appears to be a genetic component to many immune disorders. Some research has found that Gulf War illness symptoms were primarily related to vaccinations for those veterans who later reported that adverse reactions to their vaccines had occurred immediately after their vaccinations.3 Therefore, an important control variable not assessed in this study was the presence of adverse reactions subsequent to the vaccinations recorded in the database used. It might also have been useful to assess and report relationships among outcomes and vaccinations for those who had been diagnosed with immune disorders such as but not exclusive to multiple sclerosis as well as those who subsequently were so diagnosed. It must also be noted that men appear to have been underrepresented in the research relative to the entire US military (85.3%)4 for both the case (69.3%) and control groups (30.7%), which raises concerns about the generalizability of the results for the US military as a whole.
Schumm WR. Adverse Reactions to Anthrax Vaccine (eg, Optic Neuritis) May Be More Complex or Delayed Than Reported Initially by Payne et al (2006). Arch Neurol. 2007;64(3):457-458. doi:10.1001/archneur.64.3.457