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Last Updated

30 Dec 2002

Source: Washington Post, December 29, 2002


Can Smallpox Be As Simple as 1-2-3?

By William Foege

There may be comfort in having President Bush's national civilian smallpox plan, but as the mixed reactions to it show, it's not easy to get such a plan right. The administration has tried to boost confidence by having the president vaccinated last weekend and by having officials like Health and Human Services Secretary Tommy Thompson encourage medical workers to line up for their shots out of a sense of patriotic duty. But to question the plan's many assumptions or worry about the potential consequences of each phase is not a matter of patriotism. It's a matter of common sense -- and hard-won experience.

Distinctions can already be made. Phase 1, which entails voluntary vaccinations for half a million first-response health care workers, may be important for research. Phase 2, an inoculation program for up to 10 million more medical and other emergency workers, offers little protection and incurs risk. And the final phase, inoculating most of the rest of the population if needed, couldn't be implemented quickly enough as things stand now.

Most of the policymakers involved in the current discussions have no idea of the horrors of smallpox. They are simply talking numbers. But for dozens of aging smallpox warriors, this debate is different: We see faces. The faces of children who would soon be either dead or scarred for life. Adult faces covered in painful rashes oozing blood and pus. A sea of faces in a smelly, hastily constructed lean-to in Africa, where hundreds of ostracized patients were crammed in. I remember rows of sick lined up in an overcrowded Indian hospital ward. And still they came, more than 11,000 new cases in a single week in a single state of India in May 1974. Despair held sway back then, and yet out of that chaos came the lessons that broke the chains of transmission tying every victim to past and future victims -- lessons that will serve if smallpox returns.

The world has been free of this problem for 25 years. Now we face its possible reappearance in the hands of terrorists or hostile governments. A Bush administration intelligence review last month concluded that four nations besides the United States -- Iraq, North Korea, Russia and France -- hold stocks of the deadly smallpox pathogen. Nobody underestimates the gravity of the threat, least of all those medical veterans, mostly now retired, who know firsthand what smallpox means. But we also remember the problems caused by the vaccine. The sore arms and rashes were transient. The real worry came with those who developed encephalitis or whose vaccination sites kept enlarging until they had engulfed the entire arm and even then wouldn't stop. The vaccine was safe for most people, but not for all. It has been conservatively estimated that 15 out of every 1 million people vaccinated for the first time will experience life-threatening complications, and one or two will die. Those who were harmed remind us still that the benefits of the vaccine had to justify such risks.

That's why it is imperative not to regard any national plan as written in stone. The uncertainties of smallpox being used as an instrument of war must constantly be weighed against the certain risks and costs of vaccination. We know a great deal from past experience. Other things we can only learn as we go.

What do we know?

Smallpox is a distinct clinical illness, easily recognized once the level of suspicion is high. We also know that once a case is identified we can control outbreaks by quickly vaccinating contacts. This so-called ring vaccination approach was developed in 1966 and '67 and used throughout the following decade to stop numerous outbreaks, sometimes with hundreds of cases, simultaneously. Those of us in the field reached a point where we were putting all our efforts into ring vaccination rather than trying to predict in advance whom we should vaccinate. It was so much more efficient. We could do it even in a place like India, with its high population density, millions on trains at any one time and many people without actual addresses.

For anyone not involved in that effort, ring vaccination seemed -- and probably still seems -- counterintuitive. But in India we went from the highest incidence of smallpox recorded in decades in May 1974 to zero by May 1975, and there hasn't been a single case since. Compare this with the record of mass vaccination programs, which had been tried in India for more than 150 years without success. The key to fighting smallpox proved to be not background immunity but diligence in finding and vaccinating every possible contact of every patient, a goal made possible by the fact that the disease can be prevented by vaccination even three days after exposure. So there is a window of opportunity that makes outbreak control possible, even in populations with low immunity, such as the current U.S. population.

What we don't know is how the vaccinia virus, the virus used in smallpox vaccine, will behave in a population altered by HIV and other medical conditions. In the presence of smallpox we accept those risks. But in its absence, we must take these questions extremely seriously and constantly reevaluate the answers.

So what should we do? First, take comfort from Bush's reassurance that the threat is not imminent; there is time for the necessary deliberation regarding the vaccine's consequences. Phase 1 of the administration's plan, the vaccination of a few thousand health care workers, will provide data on the current vaccine's risks with minimum adverse impact on people, health care delivery and public health programs. The negative consequences could be high and must be documented as we go. Do those medical workers who have been vaccinated miss significant amounts of work? Do they spread the virus to patients? Is there a major increase in doctor visits due to post-vaccination problems or concerns? Do ongoing immunization programs get slighted? Do people attribute the risks associated with the smallpox vaccine to other, safer vaccines, and vice versa? What are the costs, and who pays them?

Then we must ask how those lessons will be utilized in Phase 2, which targets millions, including other health care workers, firefighters and police. Should we actually proceed to a Phase 2? Phase 1 will provide a core group that can safely handle potential smallpox cases. A larger circle of vaccinated people, with major gaps because of those excluded, may not provide enough security to warrant the risks of vaccination. Basing decisions on European outbreak transmission studies from decades ago may not be helpful, since those outbreaks predate experience with intensive ring vaccination as a method of control.

The other thing we can do is to prepare for the worst-case scenario -- simultaneous releases of aerosolized smallpox virus at major airports or sports stadiums, for instance. The success of the smallpox eradication campaign has made the public-health community confident that it could quickly contain and stop several, even dozens of, smallpox outbreaks if the virus were introduced here. The real question is: Could we meet the challenge if we had thousands or tens of thousands of primary cases? Not with the current plan. It is important to reassure the public by providing a plan to vaccinate the entire country within days if such an outbreak occurred. Many feel that is impossible. Yet it is no more impossible than having the entire country vote in one day.

There is no part of the vaccination process that is so complicated that it would preclude reaching everyone in the United States within three days if the risk of contagion is high. It does mean getting needed supplies in place and training volunteers, National Guard and public health workers how to vaccinate with bifurcated needles, a simple procedure that can be quickly learned. It also means strengthening the public health infrastructure throughout the country, decentralizing the job to every county, shipping vaccine nationwide overnight if the threat proves real and holding clinics in every high school. And it is critical that this be done. A plan to vaccinate the population over a matter of weeks is simply inadequate.

There is another way of utilizing the time we still have. All the current uncertainty and fear could be a non-issue if researchers were able to develop a smallpox vaccine that caused no adverse reactions. A safe vaccine could then be added to the routine childhood immunization schedule for the whole world. Smallpox as a tool for terrorism would disappear. That is, and should remain, the ultimate goal.

William Foege, professor emeritus of international health at Emory University and a fellow at the Bill and Melinda Gates Foundation, participated in smallpox eradication programs in Africa and India in the 1970s. During his tenure as director of the U.S. Centers for Disease Control and Prevention, from 1977 to 1983, smallpox was eradicated worldwide.