On the other, there is the vaccinia virus, the most dangerous of vaccinations - and the only one that can ward off smallpox.

It is the specter of this martyr, laced with deadly germs that may be stockpiled in Iraq or North Korea, that has sparked a national debate over who should be vaccinated against the disease in the coming weeks and months.

And it is the potential threat of the vaccination itself that keeps it smoldering.

Some infectious disease experts believe the known complications and side effects of the live vaccinia virus - a relative of smallpox - are too significant to ignore, especially compared to the unsubstantiated bioterror threat.

Even those who support the Bush administration's recent smallpox immunization plan acknowledge the vaccine can produce serious reactions, particularly in people with suppressed immune systems.

That risk can extend to unvaccinated people who come in close contact with the recently inoculated.

The phenomenon of ``contact vaccination'' is one reason people living in households with immune-suppressed members - including children younger than 1, pregnant women and people with cancer, lupus or AIDS - are ineligible to be inoculated under the new federal guidelines.

Patricia Wagner, a Sun City resident whose immune system has been weakened by cancer treatments, worries about the public health threat posed by the newly vaccinated.

``If it's true that a person might be slightly contagious for weeks after the inoculation, then how can sick people safely mingle in the community with those recently inoculated?'' she wondered.

The vaccinia virus can be spread from the vaccination site until a scab forms over the sore. Keeping the wound covered and washing hands frequently reduces the chance of complications or infecting others.

Health officials say the virus is unlikely to be transmitted through casual contact with people not living in the same household.

Inoculated physicians, nurses and other health care workers also are not expected to infect unvaccinated patients if they take appropriate precautions.

In Florida, some 35,000 hospital and health care workers will be offered smallpox vaccinations in late January.

By spring, as many as 400,000 of the state's ``first responders'' - police, firefighters and emergency medical workers - will decide if they want to be vaccinated.

Routine In Years Past

Each must weigh the potential benefits against the risks of being inoculated with a vaccine that, until 1972, was routinely given to the general population.

``The old program was in response to what was still considered an active disease in the world until the late '70s,'' said Daniel Haight, medical director for the Polk County Health Department.

Smallpox killed 500 million people in the 20th century alone before it was declared eradicated in nature in 1980.

In the old days, the risk of contracting the disease far outweighed the potentially serious side effects and the one or two deaths per million people vaccinated.

Today, many more people are vulnerable to complications, including anyone who is HIV positive, is receiving chemotherapy, has had an organ transplant or has a history of eczema.

For that reason, no one is recommending that average citizens line up to receive the vaccine when mass inoculations are offered next year.

In fact, health officials strenuously recommend against it under the present circumstances.

``If a weapons inspector finds evidence of smallpox stockpiles, or if there is an actual outbreak anywhere, then it's another story,'' said Haight, a member of the nine- county Tampa Bay Regional Domestic Security Task Force.

It's also another story for health care workers, who not only would play a critical frontline role in containing an outbreak, but who also are at a higher risk of exposure should the virus be unleashed.

For them, it is a matter of knowing the risk factors, knowing how to minimize the risk and making an informed choice, Haight said.

``If you're properly screened and follow directions, it's a safe vaccine,'' he said.

Some Hospitals Say No

But some hospitals have made that decision for their employees, opting not to participate in the government's smallpox plan.

Grady Memorial in Atlanta and Virginia Commonwealth University in Richmond are among the hospitals whose administrators have deemed the vaccine too risky in the absence of a clear threat of a smallpox outbreak.

So far, Tampa's H. Lee Moffitt Cancer Center & Research Institute is the only local facility that is opting not to participate.

``The overriding concern at Moffitt is its immune-suppressed patients,'' said John Greene, the hospital's chief of infectious disease.

Moffitt, unlike other hospitals in the area, also has no emergency room and would not be a destination for smallpox patients in the event of an outbreak.

If the smallpox virus were to find its way into Moffitt, the mortality rate likely would be 80 percent to 90 percent because of the patients' weakened immune systems, he said. Some doctors have expressed concern that vaccinations could bring vaccinia epidemics to hospitals, especially cancer centers, where bone marrow transplants, chemotherapy and other treatments have left patients with little immunity.

But Kent Sepkowitz, director of infection control at Memorial Sloan-Kettering Cancer Center in Manhattan, concluded after studying the medical literature that the threat was overestimated. Medical workers could be vaccinated without endangering patients as long as they keep the vaccination site covered and wash their hands often, he wrote in the New England Journal of Medicine.

Moffitt's Greene concurs. He recently was vaccinated with the vaccinia virus in case he is called upon to respond to a smallpox emergency in the community.

infobox,10p7 infohed ABOUT SMALLPOX It is a virus that no longer exists in nature. But its deadly potential as a laboratory-spawned bio-weapon has created the need to balance the risk of the disease against the risk of the vaccine that offers protection from it. subhed The Disease el,-4 b Smallpox is a serious, contagious and often fatal disease. b It kills about a third of the people it infects. b There is no effective treatment, and the only prevention is vaccination. subhed Transmission el,-4 b The virus generally spreads through direct and fairly prolonged face-to-face contact. It also spreads through contact with bodily fluids or contaminated objects. b A person is sometimes contagious with the onset of fever, but is most contagious when the rash shows up. b Contagion lasts until the last scab falls off. subhed The Vaccine el,-4 b Made from the live vaccinia virus - a relative of the smallpox virus - it can spread to other parts of the body or to other people. b The vaccine cannot give you smallpox. b It can provide immunity even after exposure to smallpox, if given before symptoms appear. b May cause rash, fever, headache and body aches. In some cases, reactions can be severe. It may cause encephalitis, especially in children. b The vaccine's protection wanes after three to five years and may offer some immunity for 10 years or more. b Anyone vaccinated prior to 1972 will need to be revaccinated. b People being revaccinated have fewer complications and milder reactions than those being vaccinated for the first time. grcredit,10p7 Source: Centers for Disease Control and Prevention Timeline 1949 - The last case of smallpox in the United States 1972 - Routine immunizations for the disease discontinued in the United States 1977 - Last naturally occurring case in the world in Somalia 1980 - Health officials declare smallpox eradicated worldwide. Source: National Centers for Disease Control and Prevention

Tribune researcher Buddy Jaudon contributed to this story. Reporter Jan Hollingsworth can be reached at (813) 259-7607.