A Drug for All Bugs

Imagine this scenario: terrorists release an airborne, antibiotic-resistant strain of anthrax in a major European capital. Without vaccines or antitoxins to reduce fatalities, the public is largely unprotected. But the government quickly dispenses a new nasal spray that puts people's immune systems into overdrive, protecting them not only against anthrax but a whole range of pathogens, including many of the deadly bioterrorist agents that governments believe are most likely to be used.

It sounds farfetched, but last week's ricin arrests in London show that the possibility of a bioterror attack is not fantasy. British Prime Minister Tony Blair...