Guide answers questions about smallpox
Smallpox is a highly contagious disease that no one is supposed to get anymore. Yet it is so dangerous – historically killing 30 percent of its victims – that the government is ready to resume vaccination against the virus, fearing that terrorists or a rogue nation might use stolen stocks as a weapon. Here are some questions and answers about the disease and the vaccine, which itself carries some serious risk for as much as a fifth of the population.
Q: Vaccines against smallpox have been used for more than 200 years. Is this a new vaccine?
A: A number of different approaches were used through the years, some using much more dangerous virus than today. The current vaccine available in the United States is made with a live smallpox cousin, called vaccinia, which arouses the human immune system so it’s ready. Although new vaccine is being made, the supply being used now is from freeze-dried vaccinia left over from the 1970s and 1980s. Vaccinations stopped in the United States in 1972; the last reported smallpox case transmitted between humans was in 1977.
Q: How is the vaccine given?
A: It is administered in a series of jabs with a two-pronged needle just under the skin, usually on the upper arm. If the vaccination “takes” a red, itchy bump develops, which then becomes a blister that eventually pops and scabs over after about two weeks. Until the site heals, the vaccinated person can spread vaccinia to other, unvaccinated people or to other parts of their own body through direct contact.
Q: What are the side effects?
A: Almost everyone has a sore arm, a low-grade fever or body aches. Studies done in the 1960s indicated that about 1,000 vaccinated people of every million suffered more serious reactions, with “life-threatening” reactions in 52 out of a million and one or two deaths. But many experts say those estimates are low. “There are a lot more people living today with compromised immune systems and other risk factors than there were when this vaccine was last given,” said Dr. Clifford Bassett, a New York University allergist.
Q: So people with HIV or transplants and some other medical treatments are at risk. Should anyone else be particularly worried?
A: People who have a history of eczema or atopic dermatitis. There also is a danger for anyone with a recent skin disease, including acne, chicken pox or psoriasis. Bassett said by some estimates, as much as 50 percent of the population is either at risk from these conditions or in close contact with someone who is at risk. The Centers for Disease Control and Prevention does not recommend the vaccine for anyone under age 18 or for women who are pregnant or about to become pregnant.
Q: Are people required to get this vaccine?
A: No. It is required for military personnel who might be sent to the Persian Gulf region and possibly Korea, about half a million in all. The vaccine is also being offered to 500,000 health care and emergency workers around the country over the next year.
Q: Can anyone else be vaccinated now?
A: The Food and Drug Administration isn’t expected to test and approve the use of any more of the vaccine for the general public until sometime in 2004. Even in the event of a smallpox outbreak, officials don’t envision mandatory vaccinations, but quarantine is possible for unvaccinated people who are exposed.
Q: What’s the thinking on the safety of the vaccine if there were an outbreak of smallpox?
A: Most experts think most people would take their chances and be vaccinated in that case, but say that’s why it’s important for people to appreciate the risks they and family members face from the vaccine versus the disease.
Q: Hasn’t there been a lot of research on the vaccine since Sept. 11?
A: A number of studies have been done, mainly on healthy volunteers, and more tests are planned of different populations, including possibly young children. Bassett points out that vaccination of the military and health workers during the next year will help guide future smallpox vaccination decisions.
Q: Does the vaccine do any good after people are exposed to smallpox?
A: The CDC says the vaccine will provide full protection to someone who gets it within three days of first exposure; it offers some protection if it’s given within four to seven days, to the extent that it would lessen the severity of illness.
Q: How long does the vaccination protect people?
A: It gives full protection for about 10 years, and some studies show immune response is preserved for another 20 or 30 years to some extent.
Q: Do people have any options if they can’t be vaccinated in time?
A: Some CDC experts say modern medical care, including new antiviral drugs and other techniques, could make smallpox much less fearsome than it was decades ago.
By some estimates, fatality rates might be as low as 2 percent among unvaccinated people who contract the disease. Some drugs and other therapies have been tested, but because the only legal stocks of smallpox are held in highly secure U.S. and Russian labs, it’s difficult to say what the actual experience would be in the event of a biological attack.
That’s why for now, the government’s main strategy is to vaccinate those who would have to care for and vaccinate everyone else if a deliberate release of smallpox were to happen.
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On the Net: www.bt.cdc.gov/ agent/smallpox