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Last Updated

20 Dec 2002

Source: New York Times, December 20, 2002.

Scientists Favoring Cautious Approach to Smallpox Shots


This article was reported by Denise Grady, William J. Broad and Donald G. McNeil Jr. and was written by Ms. Grady.

Unless a smallpox attack seems highly likely, the public should not be vaccinated, doctors and scientists warned yesterday in a series of articles posted on the Internet.

The five articles, to be published in The New England Journal of Medicine on Jan. 30 but online now at, generally express cautious acceptance of the administration's plan to begin vaccinating millions of health care and emergency workers. But because of the risks of the vaccine, the experts do not advocate mass vaccination when the risk of an attack appears low.

Government health officials have not recommended vaccinating the public but have said they would make the vaccine available to those who insist on having it, possibly as early as next year.

One article, based on a recent nationwide poll, reported that much of the public was ignorant or confused about the disease and the vaccine, and might make fatally wrong decisions if there was a real outbreak.

Another report described the difficulties encountered by doctors at a Cleveland hospital when a patient appeared with symptoms much like those of smallpox. Other articles addressed questions of how many people would be infected in possible attacks, and how likely newly vaccinated people are to infect others with vaccinia, the virus in the vaccine.

The journal did not solicit the articles, said Dr. Edward W. Campion, senior deputy editor. All were submitted independently by the authors, he said, adding, "We did rush to get these out as soon as we could because we want to inform the debate."

These were the articles' major findings:

Public Perceptions

Americans believe that smallpox is less dangerous than it really is, and that the smallpox vaccine is more dangerous than it really is, according to the nationwide survey.

The survey, by the Harvard School of Public Health, found that many Americans had serious misconceptions about the disease, misconceptions that could prove fatal because people exposed to the virus could make the wrong decisions and seek treatment too late.

"It has been a long time since Americans have had experience with smallpox and we have a shocking lack of basic understanding of it," said Dr. Robert J. Blendon, the Harvard professor of health policy and political analysis who led the study.

In an interview, Dr. Anthony S. Fauci, a top health adviser to President Bush, agreed that "the level of correct information the public has isn't high" and the government "needs to continue to hammer away at it."

The survey found that 78 percent of Americans think there is a treatment for smallpox, and 87 percent think they are likely to survive an outbreak even if they become infected. Of the respondents who were vaccinated in their youth, 46 percent believed that their old vaccinations would still protect them.

In fact, there is no treatment for smallpox, and in past outbreaks the disease has killed about 30 percent of those infected, while leaving many survivors blinded or scarred. And the immunity from inoculations received before 1972, when American doctors last routinely gave them, has probably worn off.

At the same time, the respondents seemed very nervous about smallpox vaccine. Twenty-five percent said it was likely they would die from it, and 41 percent said it was likely to make them seriously ill.

In fact, although the live vaccinia virus that protects against smallpox is the most dangerous vaccine in use, in the past it has caused only about 15 life-threatening illnesses per million vaccinations, and 1 or 2 deaths.

Fifty-eight percent of those surveyed did not realize that vaccine given in the first two or three days after exposure before symptoms appear can still stop someone from becoming sick. Only 16 percent believed there were enough doses of smallpox vaccine for everyone in the United States. Federal health officials have repeatedly said that there is more than enough because existing stocks can be safely stretched through dilution.

This combination of misconceptions is particularly dangerous, Dr. Blendon said, because, in a crisis, people would make the wrong decision.

"If people don't know that vaccine will help them if they get it immediately after exposure," he said, "and if they think there is a treatment, they would delay to see if they got sick." In a real outbreak, a two-day delay could mean the difference between life and death.

The survey found misconceptions about the disease's communicability. Although 89 percent of the respondents correctly said that smallpox was contagious, 67 percent thought it was likely that they could contract it by passing within a few feet of a carrier. Most medical experts believe that the virus is passed in closer contact, by talking face to face, for example, or sharing bed linens.

Sixty-one percent said they would choose vaccination if it were offered. But that number climbed to 75 percent if a respondent's doctor decided to be vaccinated; it dropped to 21 percent if a respondent's doctor refused vaccination.

The poll of 1,006 adults was done between Oct. 8 and Dec. 8 by ICR/International Communications Research. The margin of sampling error was plus or minus three percentage points.

Dr. Blendon said a three-pronged public education effort was needed to counteract the widespread misconceptions about smallpox and its vaccine. Most important, he said, would be televised appearances by apolitical celebrities. After Rock Hudson's death, "Elizabeth Taylor was incredibly important in explaining AIDS to the public," Dr. Blendon said.

Second, he suggested pamphlets in doctors' offices. Third, he suggested asking newspaper editors to incorporate short boxed articles with basic smallpox facts in their coverage.

Dr. Fauci, the adviser to Mr. Bush, said he thought public education efforts were already working. A few months ago, ignorance about smallpox was almost total, he said, and now much of the public realizes that there is a vaccine but that it is risky. Two government Web sites, www. and, are "flooded with public information," he said.

Risks and Benefits

In another article, researchers at the RAND Center for Domestic and International Health Security made a detailed calculation of smallpox vaccination costs and benefits that came to the same conclusion as the administration did in announcing its plan last week: that health workers should be vaccinated now but that it would be dangerous to extend the immunizations to the general public unless the risk of an attack is high.

The study estimated that if 60 percent of Americans were immunized, 482 people would die from side effects of the vaccine. That is too high a price, the researchers said, if the chance of a major smallpox attack is low.

The researchers found that some 25 people would die if nearly all 10 million health care workers in the United States were vaccinated against smallpox. They judged that cost acceptable because health care workers would come in close contact with sick people during a smallpox outbreak, making them unusually vulnerable.

"Vaccinating health workers presents a modest risk and could pay many benefits," said Dr. Samuel A. Bozzette, the study's lead author. "In contrast, a public vaccination campaign is certain to entail significant harm, so it should only be contemplated if the government concludes that the chances of a widespread attack are considerable."

The new report was based on an analysis that weighed six different possible attacks against six vaccination policies.

At the lowest level of protection studied no vaccinations until the first smallpox victims are identified the researchers said the deaths could range from zero (in the event of a hoax) to nearly 55,000 (in the event that a group of highly skilled terrorists sprayed the virus in 10 airport terminals).

The other extreme looked at vaccinating health workers and the general public before any attack. This would produce 482 deaths from complications of the vaccine, the researchers said.

Only in the case of airport attacks did the deaths from smallpox exceed those from medical complications, the study said, so only in that case would mass vaccinations save lives.

After using a computer model to weigh these kinds of tradeoffs, the scientists chose to endorse the middle path a policy of vaccinating all eligible health care workers and emergency responders before an attack. Under the administration's plan, that is up to 10.5 million people.

The study assumed that 2.72 vaccinated people in a million would die of complications, while the usual estimate is 1 or 2 in a million. The researchers said they based their estimate on a review of vaccination records.

The study noted that a mass vaccination campaign would exclude millions of people at high risk of complications, including pregnant women, babies younger than a year old and people with H.I.V. or other immune disorders or weaknesses.

But another article, by Dr. Thomas Mack of the University of Southern California, questions the need to vaccinate millions of health workers, saying 15,000 would be enough. Dr. Mack argues that outbreaks can be stopped quickly by vaccinating exposed people, and that unless the risk of an attack is high, there is no real need to expose workers to the vaccine's risks.

A Troubling False Alarm

Dealing with a potential smallpox victim may be far more complicated than doctors realize, says another report in the medical journal, this one from MetroHealth Medical Center in Cleveland.

One afternoon last May, Dr. Jennifer Hanrahan, an infectious disease specialist, was asked to examine a man with a severe, mysterious rash on his face, head, hands and legs.

He had also been sick with a headache, backache, fever, nausea and vomiting. Doctors suspected chickenpox. But some of his symptoms did not match that diagnosis: he had been sick for four days before the rash broke out, the rash was lasting too long, he had sores on the palms of his hands and all the sores on his body seemed to have erupted at the same time, rather than in stages.

Those symptoms fit the description of smallpox. If he had smallpox, a long list of health workers and others would have to be vaccinated.

Dr. Hanrahan called the local health department, which notified the Centers for Disease Control and Prevention in Atlanta. The C.D.C. wanted digital photographs of the patient's lesions e-mailed to Atlanta immediately, but the doctors lost time tracking down a digital camera.

Meanwhile, unsettling test results came back: the disease was not chickenpox.

After seeing the digital pictures, the C.D.C. wanted samples from the sores shipped overnight to Atlanta.

"This was the hard part," Dr. Hanrahan said.

The clock was ticking, but small, maddening details had to be worked out. The hospital had to call around to find a Federal Express station that would handle biological materials. Special shipping forms had to be typed, so staff members had to search for a typewriter.

The specimens were not ready to ship until 9:23 p.m. but the last flight was at 9:45. Doctors called for a police escort to the airport. They arrived on time, only to be told that the station did not accept biological specimens after all.

"That's a hurdle hospitals should be aware of," Dr. Hanrahan said, adding that the agent, seeing the police escort, made an exception for the specimens.

The next afternoon, at 3, the C.D.C. delivered its verdict: negative for smallpox. The rash was caused by a herpes virus infection that had taken a highly unusual course.

"If we had tested for herpes, we would have had the answer within an hour," Dr. Hanrahan said. "To be honest, we never thought of it. We see lots of herpes. This was not what it normally looks like."

From now on, she said, any patient who comes in with an unusual rash will be tested immediately for chickenpox, herpes and syphilis, and a digital camera and a typewriter will be quickly available.

Is the Vaccine Contagious?

A great concern of public health experts is the possibility that newly vaccinated people may make others sick by infecting them with vaccinia, a virus related to smallpox that is used to make the vaccine.

The virus is shed from the vaccination site for two or three weeks, and people who come in contact with it can become very ill if they have certain skin disorders or a weakened immune system. Doctors have been especially worried that vaccinia would be brought into hospitals by vaccinated workers and then spread among vulnerable patients.

In another article, Dr. Kent A. Sepkowitz, director of infection control at Memorial Sloan-Kettering Cancer Center in Manhattan, said that at first he feared there could be vaccinia epidemics in hospitals. But after studying the medical literature, he concluded that he had overestimated the threat and that medical workers could be vaccinated without endangering patients as long as the workers followed instructions like keeping the vaccination site covered and washing their hands often.

When he searched medical journals going back to the early 1900's, Dr. Sepkowitz said, "I think the key feature to me, looking back at these articles, is the paucity of outbreaks."

Dr. Sepkowitz said he thought hospital outbreaks would be far less likely today because patients with rashes are routinely isolated, and there is more emphasis on hand washing and covering vaccination sites.

"My main mantra is that if we go slowly we'll do fine," he said. "But if hospitals are asked to vaccinate quickly and we don't have time to figure out what we're doing and deal with surprises that are in store, we could make a mess."