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Americans Largely Ignorant About Smallpox

Survey shows many believe disease is treatable, other falsehoods

THURSDAY, Dec. 19, 2002 (HealthDayNews) -- More than three-quarters of Americans wrongly think there's an effective treatment for smallpox.

And large segments of the population believe other falsehoods about the deadly virus, according to a new survey highlighting alarming public ignorance about the disease.

The telephone survey, conducted by Harvard University researchers who polled 1,006 adults, found that 30 percent thought a case of smallpox had occurred in the United States within the past five years. The last was in 1949.

One in four thought the vaccine would likely kill them; the real risk of death is about one to two people per million inoculations.

Another 40 percent said they were likely to suffer serious side effects from the vaccine, though the actual rate is about 15 people per million. And the survey found that while the government says it has enough doses of vaccine to immunize all 286 million Americans, only 16 percent of those surveyed believe that's true.

Robert Blendon, a public policy expert at the Harvard School of Public Health and a co-author of the study, says he was "shocked" by the lack of knowledge about smallpox, despite more than a year of virtually constant media coverage. Policy makers and the medical community "have got to do something about public awareness" about the disease, Blendon says.

The survey, conducted over the last three months, is one of several studies on smallpox appearing this week in the online issue of The New England Journal of Medicine.

Smallpox was declared eradicated worldwide in 1980, but officials believe terrorists or rogue states such as Iraq and North Korea may have obtained caches of the virus.

Nearly two-thirds of people in the Harvard survey said they expected a smallpox attack in retaliation for a U.S. war against Iraq.

The studies in the journal come less than a week after President Bush ordered roughly a half million soldiers to be vaccinated against smallpox. As many as 10 million health-care and emergency workers may ultimately receive the inoculation to guard against the small threat of a terrorist attack with the virus.

Bush said he will make the vaccine available to the public on a voluntary basis starting in 2004. However, he has discouraged people from being immunized, and has said that while he will do so his family will not. Earlier this week, U.S. Health and Human Services Secretary Tommy Thompson announced that he won't be re-immunized against smallpox and that he was advising other Cabinet officials to do the same.

Yet the Harvard poll found that 56 percent of Americans support letting the public receive the vaccine, and six in 10 said they'd take the inoculation as a safeguard against a bioterror attack with the virus. That figure depended on the theoretical behavior of doctors, whose decision to get or reject the vaccine themselves raised or lowered the likelihood that a patient would elect to do so.

"There's concern [among many doctors] that many physicians are not familiar with smallpox, but the public has complete confidence in their doctors. That's whose judgment they're going to respect" in deciding whether to be vaccinated, Blendon says.

Another study in the journal, led by researchers at the RAND Center for Domestic and International Health Security, argues that mass vaccinations against smallpox are too risky to justify with only a vague threat of an outbreak. If 60 percent of the population were to be immunized, the researchers say, about 480 people would be expected to die of reactions to the vaccine.

However, the report found that a strategy of inoculating 10 million health-care workers and others on the front lines of disease containment, as President Bush has planned, is appropriate. Of that group, 25 people would likely die of vaccine-related complications. Yet the danger of narrower immunization of health workers is that in the event of an outbreak, infected patients would pass the virus to unvaccinated medical and emergency personnel before they could see workers who were protected.

"It's not a good idea to launch a widespread vaccination program across the U.S. right now because, according to the government, there's not a substantial risk of a biologic attack" with smallpox, says Dr. Sam Bozzette, an infection expert at the University of California, San Diego, and a RAND researcher.

"On the other hand, any low but non-zero risk of an attack makes a program to vaccinate health-care workers attractive, primarily because we need [them] to run the health-care system in the event of an outbreak, and because they are extraordinarily more vulnerable than others," says Bozzette, who also has an appointment at the VA San Diego Healthcare System. Health workers make up about 3 percent of the nation's population, but they would account for between 20 percent and 60 percent of smallpox cases in the event of an outbreak, Bozzette says.

The RAND researchers simulated various smallpox outbreaks, ranging from a lab sabotage to a full-scale terrorist assault on major airports. In the first scenario, they projected, seven people would die.

If three infected terrorists brought the disease to a city of 4 million -- about the size of metro Houston or Atlanta -- and each infected five people, 19 people would die before the outbreak could be contained. If terrorists released smallpox into a federal office building in a major city, 350 people might become infected and 300 might die before the disease could be heeled through targeted vaccination and isolation, the researchers say.

Simultaneous attacks on 10 major airports could lead to between about 2,700 and 54,700 deaths, depending on how many people were infected. Mass inoculations of the public and health-care workers before such an assault would lower the death toll to about 12,900 in a large-scale incident and 640 in a more limited outbreak, the study found.

What To Do

For more on the smallpox vaccine, check out Stanford University or the U.S. Centers for Disease Control and Prevention.

SOURCES: Robert Blendon, Ph.D., professor, Harvard School of Public Health, Boston; Sam Bozzette, M.D., Ph.D., professor, medicine, VA San Diego Healthcare System, University of California, San Diego, senior natural scientist, RAND, Santa Monica, Calif.; Jan. 30, 2002, The New England Journal of Medicine
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