On Aug. 8, 2007, JAMA reported that research demonstrated a strong association between early, sustained, and layered application of nonpharmaceutical interventions such as school closure; cancellation of public gatherings; and isolation and quarantine.

During the pandemic, all 43 cities in the study eventually implemented nonpharmaceutical interventions but the time of activation, duration, and choice or combination of these nonpharmaceutical interventions appear to have been key factors in their success or failure.

Most pandemic influenza policy makers agree that even the most rigorous nonpharmaceutical interventions are unlikely either to prevent a pandemic or change a population’s underlying biological susceptibility to the pandemic virus.