e suspect that many Americans were as disappointed as we were by an expert committee's recommendation that smallpox vaccine be made available only to those expected to respond to a bioterror attack and not to the general public. Yes, we know the vaccine can occasionally cause disastrous side effects and might kill hundreds and injure thousands should everyone in the nation take it. Yes, we know that the risk of a terrorist attack using smallpox is considered small and thus perhaps not worth the risk of taking the vaccine. Even so, we believe that Americans should be able to make that judgment for themselves.

Under current policy, the government makes the vaccine available to only a small number of laboratory workers, but last week, in recognition of the rising concern that terrorists might get their hands on smallpox and unleash a devastating epidemic, the Advisory Committee on Immunization Practices recommended that the vaccine be offered to some 10,000 to 20,000 medical personnel designated to cope with a smallpox outbreak should it occur.

But the advisory committee balked at recommending that the vaccine be offered to the general public. It reasoned that the risks of a smallpox attack are low whereas the known adverse effects of smallpox vaccines can be severe, killing one in every million people vaccinated and inflicting serious side effects, like long-term neurological damage, on many more. It is especially dangerous in people with compromised immune systems. Thus precautions will need to be taken to ensure that those vaccinated do not spread the vaccine virus to susceptible individuals.

The panel expressed confidence that any smallpox attack could be contained by rushing vaccine to an area where smallpox cases were detected and vaccinating everyone who had contact with the victims. That is certainly the plan, but the issue has been complicated by recent revelations that a 1971 smallpox outbreak near the Aral Sea may have been triggered by open-air testing of a Russian smallpox weapon. Should smallpox be delivered by aerosol in this country, the epidemic could spread much more rapidly than any outbreaks the public health system has previously encountered.

The great unknown is whether terrorists will be able to gain access to the smallpox virus and use it as a weapon. But the public can guess about those odds as well as an expert panel. Today, when even the intelligence agencies seem unable to estimate the risk of a smallpox attack, we should offer the vaccine and let individuals weigh the risks for themselves.