It has been 30 years since American children received routine vaccinations against smallpox. The last reported case in the United States was in 1949. The disease was declared eradicated worldwide in 1980.

Suddenly, as one more example of how the war on terrorism has changed everything, the dime-sized scar on the upper arm, once as much a generational identifier as is the ability to appreciate hip-hop, is about to once again become ubiquitous. The Bush administration’s smallpox vaccination plan calls for the immediate vaccination of some 500,000 military personnel in units that might be involved in action against Iraq. By spring, the vaccine will be offered on a voluntary basis to another half-million civilian health care workers and emergency responders. In a second phase, the vaccine will be offered to some

10 million additional health and emergency workers next summer; it will be available to the general public, but the administration does not recommend that anyone take it.

Although the deadly virus has disappeared from nature, it still exists in laboratories and may be available to rogue nations like Iraq or terrorist groups like al-Qaida. Like using commercial airliners with suicidal pilots as weapons, a smallpox strike – perhaps carried out by a lone, willingly infected “smallpox martyr” coughing his way throughout the country among innocent travelers who then spread the disease unknowingly – is unthinkable until it actually occurs. Unlike Sept. 11, this biological attack would be 10 to 14 days old – the virus’ incubation period – before anyone knew it had occurred.

The administration plan is a sensible approach to this threat. It starts with the groups that would be most in need of protection in the event of an attack. From that corps of first responders, it expands to a nationwide army of health care workers protected from the disease and trained to prevent its further spread once the first patients are hospitalized.

In announcing the plan, President Bush wisely discouraged the public from taking the vaccine. There is no evidence that a smallpox attack is imminent and the vaccine is in ample supply. The best argument against mass vaccination, though, is that this is dangerous stuff. The smallpox vaccine is a live virus that is closely related to the one that causes smallpox (another good argument is that less dangerous, non-live vaccine is now undergoing clinical trials and may be available by mid-2004). The vaccine virus can be spread by contact with the fluid that oozes from the inoculation wound for a week or more. It can cause serious health complications in as many as 90 persons per million, death in one per million.

That is where the plan falls short. Even if vaccinations are kept to the roughly 11 million military, health and emergency personnel, there could be more than 1,000 serious complications, perhaps 10 or so deaths. Add to that the 11 million chances for accidental infection from oozing wounds, and the medical costs and liability exposure are enormous.

Who will pay is one of many questions left unanswered by the recently passed Homeland Security Act. Reliance on private health insurance leaves an estimated 41 million Americans uncovered; there is no fund to compensate the families of those who may die from the vaccine; in not one state is a reaction to smallpox vaccine covered by workers’ compensation law. The vaccine’s manufacturers and those administering the vaccine are thoroughly protected under the Act. One of Congress’ first tasks when it convenes in January must be to protect, as thoroughly as possible, those who receive it.