The negative health impact of many large-scale public health emergencies, such as an intentional anthrax release, severe acute respiratory syndrome (SARS), or the recent 2009 H1N1 influenza pandemic, can be mitigated significantly by medical countermeasures such as antimicrobials, antivirals, and vaccines. To be effective, these countermeasures generally must be delivered in very large quantities in a short period of time. For example, in the event of an outdoor release of aerosolized anthrax over a wide geographic area, hundreds of thousands to millions of people would need prophylactic antibiotics within 48 hours of exposure to prevent deadly inhalational anthrax. In the event of an influenza pandemic, the timing is less urgent.
