Air Date: Week of October 19, 2001

Under the threat of bioterrorism, the nation is gearing up to provide each citizen with a vaccination against the highly contagious and often deadly disease smallpox. Host Steve Curwood talks with Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases about the smallpox threat and what's being done to offset it.

Transcript

[THEME MUSIC]

CURWOOD: This is Living on Earth, I'm Steve Curwood. The federal government is taking the first steps to protect every American against the smallpox virus. The move comes in the wake of a growing number of people being exposed to anthrax spores through acts of suspected bioterrorism. But, while anthrax can't be passed from one human to another, smallpox is highly contagious and often deadly. Right now, there are only 15 million doses of smallpox vaccine to protect nearly 300 million Americans. Joining me to discuss smallpox preparedness is Dr. Anthony Fauci. He is director of the National Institute of Allergy and Infectious Diseases. Dr. Fauci, why would smallpox be a dangerous weapon in the modern world?

FAUCI: Well, the reason it would be a dangerous weapon is that because of our own successes in the elimination and eradication of smallpox worldwide, that we have discontinued, I think appropriately, the routine vaccination of the American public, and that was discontinued back in 1972. Which means that we have a population of people in the United States, many of whom never had a vaccination, and many of whom who did had it many years ago, to the point where you wouldn't have a high degree of effective immunity. So we have a situation where, if smallpox were reintroduced into the population in a bioterrorism manner, that you have people who would not be protected as they were decades ago when routine vaccinations occurred. The other major difference, and it's a significant difference, between the anthrax threat and the smallpox threat, is that smallpox is efficiently transmitted from one person to another. Whereas, anthrax as a bioterrorism weapon is one that if you get directly exposed to the anthrax spore you have a problem, but you cannot transmit anthrax to another person. So you can amplify the effect of a bioterrorism incident if you have a microbe, in this case a virus, smallpox, that can be transmitted readily from one person to another.

CURWOOD: Can you describe what happens when someone contracts smallpox?

FAUCI: Yeah. Well, smallpox is a disease that goes as follows. If you're exposed, for example, on what we'll call Day 0, about 12 days later you start to develop a very serious flu-like illness. And then over a period of a couple of days you develop a reddish, slightly-raised rash on your body that generally starts off on the face and the upper and lower extremities and then ultimately gets to the trunk. Within a period of a few days that rash evolves into papules and then pustules and you get the classical large pustules that you see in individuals, who you have pictures of, who have smallpox. And then, over a period of a couple of weeks those pustules then start to scab, the scab ultimately falls off. If the patient survives, there are very disfiguring pockmarks that are left, throughout the skin, where those pustules were. About 30 percent of individuals, in some epidemics, would die from smallpox, and the rest might have some serious residual complications.

CURWOOD: So, how many doses of smallpox vaccine does the U.S. have stockpiled today?

FAUCI: We have stockpiled about 15 million doses, but we're doing a study, literally as we speak, that is going to ask the question, can you dilute that, either one to ten or one to five, to markedly expand and amplify that stockpile? We have some preliminary evidence to think that one to ten gives you about a 70 percent take, as we call it, and you can determine if the vaccination will likely work if you have a characteristic skin lesion as a result of the application. We're doing a larger study, now, to look at one to ten versus one to five. So let's assume that a one to five dilution actually is effective in giving you a high rate of take. Then right away you can amplify the stores that you have of smallpox vaccine from 15 million to 75 or more million. So that's a very good start, and that can be done relatively quickly. Simultaneous with that, there's a dramatic scaling up of the production of a second generation of smallpox vaccine.

CURWOOD: How will you use this vaccine when it's developed?

FAUCI: It will be kept in reserve, because you don't want to vaccinate people unless you actually have the reappearance of smallpox in society, because these vaccines have a degree of toxicity. You'd want to have it in reserve just in case something happened.

CURWOOD: How does this vaccine work? When in the course of an outbreak must it be administered to be useful?

FAUCI: Well, if someone is not exposed but has the potential for being exposed, you would want to vaccinate the people who are within the proximal area of where the index case is. There is evidence to show that even if someone does directly get exposed, and infected, that you have about a four day period in which when you vaccinate the person, even after they have become exposed, that you can ward off the evolution of disease.

CURWOOD: I understand there's some concern that the former Soviet Union had genetically engineered a new variety of smallpox. How well might the vaccine we currently have work against this genetically engineered strain, if it exists?

FAUCI: I don't know about the Soviet Union's genetic manipulations but one cannot say, necessarily, that if you genetically manipulate it, that the body's immune response would not be able to still protect you against the smallpox disease.

CURWOOD: In the absence of vaccine, doctor, what are some of the other defenses the medical establishment has against smallpox?

FAUCI: Well, there aren't very many except good care of people who go through this rather terrible illness. There are some experimental antiviral drugs that we are looking at right now, that have shown promising results in an animal model. The name of the antiviral that we're looking at, and there are others in the pipeline, is an antiviral called cidofovir, which was originally developed for a different type of virus mostly seen in H.I.V. infected individuals.

CURWOOD: By the way, what role should vaccines play, in any, in the concerns about anthrax?

FAUCI: Well, again, since there is not a lot of vaccine available at this particular moment, and since the anthrax thus far has shown to be quite sensitive in being able to be controlled by the appropriate and expeditious application of antimicrobial therapy, vaccine does not play nearly the same role that it would play for example in a disease like smallpox. So, although we are working - and this is more of an intermediate long-range affair - to have vaccine that's less toxic than the current one, easier to make and easier to induce immunity so that we could have stockpiles of very, very large amounts of vaccine if we ultimately need it. But we do have that stopgap measure of antibiotics, which seem, in this current terrible situation in we're in of bioterrorism, seems to be curtaining and curtailing the evolution of disease rather rapidly. So that the bioterrorism that's occurring now is very heavy on the terror component and moderate and light, in the big picture of things, on the medical implications of it.

CURWOOD: Meaning that there are not a large number of people being affected?

FAUCI: Well, right. I mean, people are being exposed, but there's a very small number of people, relatively speaking, who actually have gotten infected.

CURWOOD: Dr. Anthony Fauci is director of the National Institute of Allergy and Infectious Diseases, at the N.I.H. Thanks for sparing a moment to talk with us today, Dr. Fauci.

FAUCI: You're quite welcome.

 

Links

CDC Smallpox page
Medline Encyclopedia page on smallpox">