On November 27, with the United States still reeling from the attacks on the World Trade Center and the series of anthrax-spiked letters, legislators at a hearing on Capitol Hill got more shocking news. They learned that the country was ill prepared to deal with future attacks from microbes-and not just the kind released by terrorists. One expert after another testified to the Senate's Committee on Health, Education, Labor and Pensions that in the past year the country had suffered various shortages of the vaccines critical to fighting infectious diseases. The witnesses' warnings went beyond the threats of anthrax and smallpox, describing a chronic lack of vaccines for common influenza, which claims 20,000 American lives a year, and the childhood menaces tetanus, pertussis, diphtheria and pneumococcal disease.

These problems are not new. But they took on an unprecedented sense of urgency after September 11, when it became apparent that the country had paltry supplies of smallpox and anthrax vaccines on hand-and no vaccines whatsoever for many other potential bioweapons. What's more, it was also obvious that the United States lacked the manufacturing infrastructure to quickly remedy the problem, or deal with a widespread epidemic of anything from smallpox to the flu. "These shortages call into serious question our ability to continue to meet the public-health needs of our citizens," said Senator Jack Reed, a democrat from Rhode Island, at the opening of the hearing.

The situation is largely a result of the failure of market forces to encourage vaccine production, which is a risky and far from lucrative business. Only four large pharmaceutical companies in the world still make vaccines. And while the four manufacturers compete on some vaccines, and several biotechnology companies are attempting to fill in gaps, the general lack of competition means that shortages occur routinely. Seemingly minor glitches can interrupt supplies: a business decision, a regulatory ruling or trouble in a laboratory or manufacturing plant.

Fear of a looming health crisis is, for the first time, prompting scientists, industry leaders and policymakers to take a sweeping look at the nation's vaccine needs, both exotic and routine. One bold solution: a proposal to supplement private vaccine production with a federal initiative. This scheme calls for the U.S. government to establish a National Vaccine Authority to oversee research, development and distribution of vaccines that are too risky or too unprofitable for industry to make. A central component would be a government-owned, contractor-operated vaccine-manufacturing plant.