In late January, New York City will receive 15,000 doses of smallpox vaccine to begin voluntary vaccination of health care workers as part of President Bush's homeland security initiative.
If vaccination of health care workers goes well, other "first responders" like police and firefighters will then be vaccinated, and the shot will be made available in 2004 to members of the general public who want it.
But the vaccination campaign raises many questions. How safe is smallpox vaccination? Do people over 34, who were vaccinated as children, still have protection or do they require booster shots? Should the general public seek vaccination? And how likely it is anyway that smallpox will be used as a biological weapon?
The last question is critical for answering the first. If the chances of an attack are exceedingly low, the risks of vaccination almost certainly outweigh the benefits. The currently existing vaccine, which is basically a variant of the first vaccine ever developed (by Edward Jenner, in 1796, is the most dangerous vaccine still in use. It kills 1-2 people per million and causes life-threatening illness in about 14-52 people per million, according to the federal Centers for Disease Control.
The vaccine uses a live virus, vaccinia, which is a relative of the cowpox virus that Jenner first observed to protect milkmaids from developing the far more deadly smallpox. Most of today's vaccinations use dead or inactivated viruses, so they are far less likely to have serious side effects. Because smallpox vaccination uses a live virus, however, people who are vaccinated can actually infect others with it-- if people who have not been exposed previously touch the vaccination site or otherwise come in contact with fluids from it.
About 1 in 1000 vaccinated people will have a serious, but not life-threatening response, such as a rash which spreads from the vaccination site. Sore arms and fever were common in recent tests of the vaccine conducted to aid the government's decision on widespread vaccination. The tests compared full dose vaccine to diluted versions. This research needed to be conducted because without dilution, there isn't enough existing vaccine to protect the population.
Out of nearly 700 young adults (mainly college students) who volunteered to take the shot, over one third stayed home from school or work for a day and about nine percent developed fevers. Fourteen percent developed rashes which spread beyond the vaccination site. All strengths of the vaccine were effective in this test. There were no deaths.
Today's population, however, is at higher risk from the vaccine than populations that were vaccinated earlier. For example, people with HIV could become seriously ill if they were vaccinated or exposed to virus from vaccinated people. Other people at high risk include people with any form of immune suppression (transplant patients, people on steroids for auto-immune disorders), pregnant women, people with certain skin diseases such as eczema or atopic dermatitis and those who are allergic to certain antibiotics which are contained in the vaccine. Researchers estimate that about 15 percent of the population currently has at least one of these risk factors.
Andrew Stern, the president of the SEIU (the largest national health care workers's union), released a statement in December saying, "The Administration and Congress have protected the wealth of the drug companies who make the vaccine, but not the health of hospital workers and the public. President Bush's smallpox plan will put thousands of Americans at unnecessary risk." SEIU Local 1199 will hold a forum in late January to plan the local union's reponse to the city's vaccination efforts and discuss whether they will recommend vaccination, which is voluntary, to their members.
"We want to make sure all possible risks are weighed, for health care workers, hospital patients and their families," said Dieter Metzger, a spokesperson for the union. Amongst 1199's concerns are the lack of provisions for time off for those who have bad reactions to the vaccine, protection from spread of vaccinia to vulnerable workers and patients, and protection from discrimination for workers who choose not to be vaccinated.
So how dangerous is smallpox itself?. In the past, it killed about one-third of those who were infected. Now, experts think mortality would be lower because many smallpox deaths resulted from bacterial infections which often develop on the "pox" (Note, graphic image) or sores, which cover the bodies of victims. Antibiotics can now easily treat such infections. Also, people can be vaccinated to avoid illness within three to four days of exposure, leaving a window of time for rapid vaccination in event of a terror attack.
And while there is currently no treatment approved for smallpox, a new antiviral drug, cidofovir, has been found to be effective in culture and in mice. Researchers are testing an oral form of this drug; an injectable version is already approved for treatment of a common opportunistic infection of the eyes seen in people with AIDS, called CMV retinitis.
Further, everyone over 34 has been vaccinated at least once. A review of smallpox cases in Europe and Canada in the 20th century found that 52 percent of unvaccinated people died, but only 1.4 percent of cases were fatal for people vaccinated within 10 years and the mortality rate for those vaccinated from 20-50 years prior was 11 percent. A more recent study also suggests on-going protection, showing a strong immune response by cultured cells in people vaccinated between 6 and 35 years ago. Researchers are not sure how generalizable these studies are but the World Health Organization's smallpox fact sheet suggests at least some protection.
The last cases of smallpox to hit New York occurred in 1947. At that time, a businessman visiting from Mexico became ill with the disease and infected 12 other people. Two of them died -- but the city prevented further spread of the illness by vaccinating 6 million people in one month.
Complications from the vaccine killed six people, ironically, more than the disease did.
A country which is at possibly the highest risk for terrorism in the world, Israel, has already vaccinated 17,000 of its soldiers, police and health care workers and plans to vaccinate more. So far, there have been only two serious negative reactions and no deaths. But on Christmas day 2002, Israel announced that it would not vaccinate its entire population, declaring the risk of a smallpox attack to be low.
When the risk of disease is so hard to determine, deciding on use of a risky vaccine is extremely difficult. People over 34 tend to wonder what the big deal is, and why something that all of us received as kids is now seen as so dangerous as to make even clinical trials on children unethical (a recent plan to test the diluted vaccine was stopped by critics). The issue is context. Smallpox was a real threat until 1977, when the World Health Organization declared that it was eradicated. A 30-50 percent chance of death is certainly a greater risk than a 1-2 in a million risk.
It took enormous effort by thousands of dedicated doctors, scientists, public health workers, nurses and others around the world to eradicate the smallpox virus, which had long been one of humanity's greatest foes. Smallpox is believed to have killed more people than any other infectious disease, claiming 300 million lives in the 20th century alone.
Communists, capitalists and others across boundaries worked together to ensure the end of the virus, which was then stored only in two sites by the U.S. and the former Soviet Union. Stolen virus from the former Soviet facility, which was less than secure as Soviet rule ended, is believed to be the source for any virus potentially obtained by terrorists.
Unleashing such a threat after such an effort can only be seen as an attack on civilization itself. Let's hope it doesn't happen and that the risk from the vaccine is the greater. But unfortunately, right now, we just don't know.
Maia Szalavitz is author, with Dr. Joseph Volpicelli, of "Recovery Options: The Complete Guide: How You and Your Loved Ones Can Understand and Treat Alcohol and Other Drug Problems." She writes frequently on health, science and public policy for the New York Times, New York Magazine, the Village Voice, and other publications.
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