Posted on 10/27/2001 10:21:30 AM PDT by ignatz_q
And Now, the Good News About Smallpox - In the event of a terrorist attack, we're not all toast. By JonCohen
By JonCohen
Updated Friday, October 26, 2001, at 10:38 PM PT
If you received a smallpox vaccine in infancy, as most everyone did in the United Statesbefore routine immunizations stopped in 1972, your immunity to this disfiguring and often lethal disease certainly has waned. Indeed, authoritative sources would have you believe that you have no immunity whatsoever. But if you dig out original scientific studies about the smallpox vaccine, a much different-and a much more optimistic-picture emerges.
According to U.S. Census Bureau data, about 40 percent of the U.S. population is 29 or younger, and having never received a smallpox immunization, up to 30 percent of that cohort would die if infected with the virus during a bioterrorist attack. But what of the remainder of the population, the 60 percent that got the vaccine at one point or another? What is their vulnerability?
The Centers for Disease Control and Prevention Web site offers this depressing answer in a smallpox FAQ: "Most estimates suggest immunity from vaccination lasts 3 to 5 years." In 1999, leading experts offered similar estimates in a "consensus statement" on smallpox as a biological weapon that they published in the Journal of the American Medical Association. "Because comparatively few persons today have been successfully vaccinated on more than 1 occasion, it must be assumed that the population at large is highly susceptible to infection," they concluded. "Dark Winter," a war game conducted in June at Andrews Air Force Base in which a smallpox "attack" was launched, proposed that 80 percent of the U.S. population is susceptible to the disease.
But data from a 1902-1903 smallpox outbreak in Liverpool, England, strongly suggests otherwise. A study analyzed the impact of the disease on 1,163 Liverpudlians, 943 who received the vaccine during infancy, and 220 who were never vaccinated. The study further separated people by age and by the severity of their disease. In the oldest age group, 50 and above, 93 percent of the vaccinated people escaped severe disease and death. In contrast, 50 percent of the unvaccinated in that age bracket died, and another 25 percent had severe disease. To put it plainly, the vaccine offered remarkable protection after 50 years.
Frank Fenner, a virologist at Australia's John Curtin School of Medicine who co-authored Smallpox and Its Eradication-a 1,400-page book that is the field's bible-says the Liverpool study remains the best evidence that vaccine immunity lasts for decades. The Liverpool study, paradoxically, also helped create the common wisdom that vaccine immunity rapidly wanes. In the Liverpool study, Fenner notes, vaccinated kids who were 14 and younger had zero cases of severe disease or death. So out of "conservatism," he explains, many smallpox experts began to advocate that anyone in an area where smallpox exists should be revaccinated every decade (Australia went one step further and said every five years). An added benefit of this aggressive vaccination policy was that it also slowed the spread of smallpox, because recently vaccinated people were less likely to transmit the virus than those who had received their immunizations decades before.
More recent data supports the Liverpool experience. In a 1996 study published in the Journal of Virology, a group led by Francis Ennis at the University of Massachusetts Medical Center pulled immune cells out of people who had received the smallpox vaccine decades before. When they tickled these cells to see whether they remembered the lesson the vaccine had taught them, they found that "immunity can persist for up to 50 years after immunization against smallpox."
James Leduc, the CDC's resident smallpox authority, concedes that the conventional wisdom posted on the CDC's Web site might not tell the whole story. "The issues that you are raising are absolutely accurate and well founded," he says. "What you see on the Web site is a first attempt to get a consistent message out," he says, explaining that the public health quandaries-such as the need to produce more vaccine-sometimes overshadow the scientific ones.
Fenner, like several other smallpox experts queried, has no idea how much protective immunity exists now in the United States. "Oh, gosh, it is a guess," he says. But as Bernard Moss, a researcher who works with the smallpox vaccine at the National Institute of Allergy and Infectious Diseases, stresses, a vaccine simply gives the immune system a head start in the race against a bug. In the case of smallpox, the bug is fairly slow to cause disease-symptoms typically don't surface for a few weeks-and an infection in a vaccinated person can act like a booster shot, revving up an already primed immune system. "Everyone would agree that if you had a vaccination in your life," says Moss, "you're much better off than if you hadn't."
None of this good news argues against rebuilding the nation's smallpox vaccine stockpile, which has dwindled to a mere 15.4 million doses. (The federal government has committed more than $500 million to produce 300 million doses.) Regardless of our country's precise immune status against smallpox, widespread use of the vaccine during outbreaks repeatedly has worked: New York City dramatically aborted an epidemic in 1947 with a rapid and aggressive vaccination (and, importantly, isolation of victims) campaign that limited the spread to 12 cases and two deaths. And surely we have become more vulnerable to smallpox since routine immunizations stopped.
But the good news inspires the sort of confidence the country needs right now: The entire population isn't at extreme risk in the event of a smallpox attack. As the CDC's Leduc says, "This is not going to be a wildfire that overtakes the world."
Related in Slate
For the good news on anthrax, see this previous Slate piece by Jon Cohen.
The gravity of this is almost too much to process. I had my vaccine back in 1956. My husband had his in 1955 or 1956. Our son, who is 22, was not vaccinated. I am totally enraged at the mere thought.
However, it is bound to spread to other parts of the world where they don't have money for prevention. It is bound to get back to the middle east, with international travel the way it is now. Far more of them will die.
I can understand that, but I'm not so angry about the situation. For one thing, there is still exactly zero evidence that any smallpox exists except for two tiny, secure amounts in disease research facilities in the U.S. and Russia. For another, the disease does seem to be erradicated as a natural pathogen.
I'm not trying to downplay the possibility that it could be used for an attack, but the odds are much, much Even if Iraq or a terrorist group has smallpox, it's very hard to handle safely, and even harder to deliver effectively. I want us to start stockpiling vaccine to be safe, but I'm just not sure that mass-innoculation is the answer at this point.
Honestly, at the first sign of smallpox, I'm gonna go find some cows and vaccinate myself. Anyone have James Herriot's number, because I don't know what cowpox looks like.
It also means that if the 15 million doses on hand can be effectively diluted to 75 million (the CDC's stated goal), the real target population for the vaccine is down to around 110 to 120 million.
We could make giant strides toward "herd immunity" in a hurry, in the event of an emergency.
Why?
They're goading us into a war that will go worse for them than us, whatever happens. But they're still spoiling for a fight.
Brings a whole new meaning to the phrase, "It's for the children.".
My mother vaccinated me herself at a time when it was becoming less common to give smallpox vaccines (she was a nurse). My doctor had not ordered one for me. Since all this talk about smallpox, I have been thinking that it has to count for something, even thirty or so years after the fact. Maybe it will make the difference between life and death, or the difference between a mild case and a severe one. My mother has also been thinking about this, and she's glad she vaccinated me.
What did C.S. Lewis say about men without chests?
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