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.
Several folks have mentioned other places to look if you don't find it on the upper arm. Mine is on the underside of the upper arm to avoid the unsightly scar problem. Other places mentioned were hip and buttocks.
twinzmommy
Are you an Epidemiologist? Neither am I, so our estimates are equally worthless. However, I am really fascinated by people on FR who blithely throw around figures like "about 5%" deaths, as though that were a GOOD THING!
Now, if the attack rate were 100%, a case fatality rate of "about 5%" would mean "about" fifteen MILLION dead Americans. Of course, no disease has an attack rate of 100%, so let's bring that down to a more realistic 10% for the entire country (much higher in some cities, lower in some rural areas). That still gives something like 1.5 MILLION deaths.
If smallpox is released in North America, I am certain that someone will make sure that it gets back to the near/middle east.
You appear to be a genius at "missing the point"-
I have read this entire thread, and am amazed at the reaction to TomB's posts. He makes total sense, and it concurs with the KNOWN data. Sure, there are studies that show potential disaster, but they try to be realistically pessimistic, because the HAVE to be prepared for the worst case disaster. Turns out that the worst case scenerio is not likely, I think thats good news. Not that we should not be vigilant, but I think we should be realistic.
I am amused to see quite a few people almost WANTING to believe the worst about things and reacting so negatively to TomB. I suppose some people secretly want to think the worst...
You are correct and it is surprising the hell out of me. It's palpable and sweaty.
The realitiy is that some poor kids need a lot more wrong with them than just a fever, a cough, and a rash before they are taken in for medical care.
is ridiculous, because once it is announced that smallpox is occurring in a given area, anytime a person gets sick they will assume is the diesase, as anyone paying attention to what is going on with anthrax right now can plainly see. You also continue to ignore the fact that the disease is not contagious for 2-3 days after the person gets sick.
Tom, the flaw in your thinking is that you assume that if the terrorists hit us with smallpox, it will be in ONE place. There is good reason to think that they would hit us in multiple, widely separated locations simultaneously. This has been SOP for the Al Qaida network. They hijacked 4 planes on 9/11 (and may have had teams trying for more). They bombed two embassys in Africa a couple of years ago. Anthrax was mailed to multiple recipients.
Do you have ANY good reason to believe that THIS TIME, the authorities are not immediately going to come out with the automatic disclaimer that the first reported case is an "isolated incident"? That is exactly what they did with the anthrax, yet the truth was that they DID NOT REALLY KNOW whether or not this truly was just an isolated case or part of a larger, broader attack. They did not realize and admit that the attack was larger and broader than they initially thought until many days later.
Perhaps they will perform better this time around. However, given that smallpox is a much more deadly serious threat, I'm not at all sure that parents are going to want to make that gamble with their children's lives.
Like I said, those reports are about possibilities, as you stated. What we have are data that shows that those possiblilities might not be probabilities. I dont think that the discussion of these two ranges of possibilities are incompatible with each other. As of now, we have heard of the more pessimistic possibilities. With the introduction of data to support something less catastrophic, some have come out of the woodwork to denounce it. I dont think that is neccessary.
I read the whole thing. Took over an hour.
Have to go to bed now.
Thanks for the link. Everyone should read it.
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