After small-scale anthrax attack: vaccinate, treat

NEW YORK (Reuters Health) - In planning for the possibility of a small-scale bioterrorist anthrax attack like the one perpetrated via the US mail in 2001, the most cost-effective response is to vaccinate exposed persons and treat them with antibiotics, new research hints.

By contrast, pre-attack vaccination of postal workers in all mail distribution centers is more costly and less effective, according to the report in the Archives of Internal Medicine.

Dr. Brian Schmitt, from the Hines VA Hospital in Illinois, and colleagues used Monte Carlo simulation over a 10-year time frame from a societal perspective to assess the most cost-effective response to an anthrax attack through US mail distribution centers in a large metropolitan area.

They compared three responses: pre-attack vaccination, post-attack antibiotic therapy with vaccination of exposed personnel, and post-attack antibiotic therapy without vaccination. They used published data and opinions from bioterrorist experts to estimate the likelihood of infection after anthrax exposure, vaccine and antibiotic benefits/risks/costs, and associated outcomes.

As noted, the most cost-effective strategy was to combine post-attack antibiotic therapy with vaccination of exposed personnel. Compared with post-attack antibiotic therapy alone, the incremental cost-effectiveness of this strategy was $59,558 per quality-adjusted life year, which represents a year of being healthy.

Pre-attack vaccination of all distribution workers costs nearly $2.6 million per QALY relative to post-attack antibiotic therapy alone, and that is assuming full adherence, the authors point out.

“Our results suggest that post-attack antibiotic therapy alone may be preferred when response time is rapid (within 12 hours), which is feasible given the presence of the autonomous detection systems in postal offices,” the authors state. “Development of a plan for rapid delivery of treatment (vaccination and antibiotic therapy) is critical for successful mitigation of a future attack.”

SOURCE: Archives of Internal Medicine April 10, 2007.