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The how and why of smallpox shots

Why has smallpox re-emerged as a potential terror weapon and a target for immunization? MSNBC’s Alan Boyle traces the fall and rise of a phantom menace.
That was then: In April 1947, people stand in line waiting to be inoculated against smallpox at the Morrisania Hospital in New York.
That was then: In April 1947, people stand in line waiting to be inoculated against smallpox at the Morrisania Hospital in New York.
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Why has smallpox re-emerged as a target for vaccinations, even though the deadly disease was eradicated a quarter-century ago? If it poses even a potential threat, why aren’t we immediately going back to the days of total vaccination? The answers demonstrate how the world has changed since the first Gulf War — not only due to the rise of terrorism, but also the fall of the Soviet Union, the spread of AIDS and a fuller appreciation of the medical risks.

Sparked by fears that Iraq or even al-Qaida operatives could use smallpox as a bioterror weapon, the Bush administration has laid out a plan to resume widescale smallpox vaccinations in the United States, 30 years after they were discontinued.

This marks the first time that a nationwide public-health effort has been undertaken solely as a protective measure against a potential biological weapon, since smallpox no longer exists as a naturally occurring disease.

It wasn’t always that way: For thousands of years, the smallpox virus was one of humanity’s greatest scourges, killing hundreds of millions. Finally, thanks to a worldwide immunization program, the last naturally acquired case of smallpox was recorded in Somalia in 1977.

But even as smallpox was being eliminated in the wild, U.S. and Soviet laboratories were developing the virus as a bioweapon — and now experts worry that, during the Soviet death throes, scientists motivated by ideology or money shared weaponized strains of the virus with nations such as Iraq and North Korea.

During the Iraq crisis in 1990-91, U.S. military personnel were inoculated against a variety of biological threats — but not against smallpox. “There wasn’t a concern in the first Gulf War,” said Dr. Sue Bailey, former assistant secretary of defense for health affairs. Now, she said, “there is intelligence that tells us this is a higher risk.”

Among the evidence:

Soviet defector Ken Alibek said last year that Moscow was developing a smallpox strain that might have been used as a post-doomsday weapon. Now, the CIA is worried that the late Russian virologist Nelja Maltseva may have shared just such a vaccine-resistant strain with the Iraqis, a senior U.S. official told NBC News, confirming a New York Times report.

U.N. weapons inspectors gathered several hints of an Iraqi pox research program, including the discovery of a freeze-drier labeled “smallpox” and an Iraqi admission that it had conducted experiments with camelpox, a cousin to smallpox.

Pentagon medical investigators say eight of 69 Iraqi prisoners of war who underwent blood tests in the Gulf War’s wake had built up immunity to the smallpox virus, hinting at prior vaccination.

Most U.S. experts on bioweapons assume there’s additional, classified evidence driving the Bush administration’s calculations.

A public health simulation conducted in June 2001, code-named Dark Winter, indicated that the United States was unprepared for a smallpox attack, and last year’s terror attacks and anthrax-related deaths added to the alarm.

“Since Sept. 11, we have learned that the world can be a very dangerous and changing place,” said Curtis Allen, a spokesman for the federal Centers for Disease Control and Prevention, “and therefore it is only prudent to prepare for any eventuality.”

So why not immunize everyone?
Historically, the live virus in the smallpox vaccine killed one or two people out of every 1 million who were vaccinated, and many others suffered debilitating side effects.

The risk is heightened for those who have suffered from eczema or other skin diseases, as well as those whose immune systems have been compromised — such as HIV patients, transplant recipients and cancer patients. There are more people with those conditions today than there were 30 years ago, so mortality rates could be higher.

Thus, if every U.S. resident were vaccinated, 300 or more might die as a result. That also happens to be one of the figures quoted for the projected death toll from a bioterror attack using smallpox.

“It’s a difficult tradeoff, because there are wide uncertainties as to what an attack might involve,” said David Ropeik, director of risk communications at the Harvard Center for Risk Analysis. “On the low end, it seems to match the number of people who might be killed from the side effects of the vaccine, but I’ve seen much bigger numbers than that. Because there’s uncertainty, it makes a strictly fact-based risk analysis decision impossible.”

What is to be done?
This is why the Bush administration is starting with the front lines in a phantom war — not because there’s a dearth of vaccine, but because there’s a dearth of information. Emergency workers would be less likely to fit the profile for serious side effects, and scientists would have an opportunity to look out for potential problems as the immunization target group expands.

“If something does happen, they’ll be able to cut it off,” said Dr. Richard Pilch, scientist-in-residence at the Center for Nonproliferation Studies at the Monterey Institute of International Studies.

On the other hand, if there is an outbreak, the scope of vaccinations would quickly widen. If it’s administered even a few days after infection, the vaccine appears to ease the severity of the disease.

Meanwhile, scientists are working on longer-term strategies to fight future smallpox attacks: genetically engineered vaccines that don’t produce the current side effects, as well as antiviral agents that could for the first time truly treat the disease.

NBC News producer Robert Windrem contributed to this report.