The smallpox dilemma
The Bush administration has launched a volunteer plan to vaccinate health workers against smallpox, and eventually will offer the vaccine to all Americans. So far, very few have lined up. Why?
Do terrorists have smallpox?They might. Smallpox disappeared from nature back in 1980, after a heroic worldwide effort to eradicate the disease through vaccinations. The U.S. and the Soviet Union, though, kept a few vials of the deadly virus in storage, and the Soviets worked to weaponize it for use in war. They cultivated highly lethal strains and suspended them in a liquid, so smallpox could be loaded into intercontinental ballistic missiles and long-range bombers. When the Soviet Union fell in 1991, the clandestine research stopped. But intelligence reports indicate that Soviet scientistssuddenly lacking an incomemay have sold smallpox on the black market, and that Iraq, North Korea, and even France may have bought some. After Sept. 11 and the anthrax-tainted letters that killed five Americans, the administration became deeply worried that bioterrorists might launch another attack, this time with smallpox.
Why so much concern?Smallpox is one of the most contagious and vicious scourges known to man. In just the 20th century alone, smallpox killed more than 500 million peoplemore casualties than in all the wars of that century combined. The variola virus that causes smallpox can spread like fire through dry grass; it is transmitted through direct contact with other infected people or contaminated objects such as clothing or blankets. Smallpox starts with a fever that spikes as high as 104 degrees, head and body aches, and sometimes vomiting. A rash follows, which spreads and becomes raised bumps; these progress to pus-filled blisters that then develop scabs. The disease kills about 30 percent of its victims, and the pox, which generally lasts about three weeks, can be excruciatingly painful as well as gruesome. About one in 10 survivors becomes blind; nearly all are disfigured by pockmarks.
Is there any treatment?Getting vaccinated within three days of exposure to smallpox will help reduce or prevent symptoms, but there is no proven treatment. Experts believe the anti-viral drug cidofovir may help, but the only way theyll find out is if theres an outbreak.
How does the vaccine work?Most modern vaccines use a dead virus or parts of a virus to stimulate immunity. Created decades ago, the smallpox vaccine uses a live vaccinia virusa genetic relative of smallpox. Once exposed to this virus, the body makes antibodies that also recognize and disarm smallpox. The vaccine is given using a two-pronged needle dipped into the vaccine and pricked many times into the skin. After a few days, a red, itchy bump appears, which turns into a pus-filled blister; eventually a scab forms that leaves a permanent pockmark. The Centers for Disease Control and Prevention says the vaccine is 95 percent effective.
What if you had the vaccine in childhood?Its unclear whether theres any residual immunity. Routine smallpox vaccination stopped in the U.S. in 1972. The vaccine provides high-level immunity for three to five years and decreasing immunity thereafter, said the CDC. But if a person was vaccinated more than once, its possible he or she still has some immunity. The National Institutes of Health is doing a clinical trial to find out.
How safe is the vaccine?Because a live virus is used, a relatively high number of people develop negative reactions. Some even die. In a recent report, the Institute of Medicine, part of the National Academy of Sciences, said the smallpox vaccine may be the least safe vaccine ever used on a large scale. For every 1 million people vaccinated, the government says, one to two people will die. Another 14 to 52 will have life-threatening reactions. These include progressive vaccinia, in which the live vaccinia virus spreads through the body; eczema vaccinatum, a serious skin reaction; and encephalitis, or swelling of the brain.
What is the governments vaccine plan?In the first phase, now underway, 500,000 military personnel are having mandatory vaccinations. That will protect soldiers who might be exposed to smallpox on the battlefield. Another 500,000 health-care and emergency workersthose most likely to be exposed to someone who has contracted smallpoxare being offered the vaccine. In a second phase, it will be made available to another 10 million health-care, law-enforcement, and emergency-response people. Sometime this year or next, the vaccine may be offered to the general public, although its not being recommended now.
How is it being received?With great trepidation. The problem is that the threat of smallpoxhowever graveremains hypothetical, based entirely on a terrorist attack that may or may not ever occur. But the risk of the vaccine is immediate and real. So far, about 350 hospitals nationwide have decided not to vaccinate. As of last week, the CDC said just 1,043 people out of a possible 500,000 had been vaccinated. The thing that stops you from doing this is the complexity of the smallpox vaccine, which is not a safe vaccine, Dr. William Schaffner, head of preventive medicine at Vanderbilt University Medical Center in Nashville, told USA Today. Show me one case of smallpox in the world, and I would change my mind immediately.
The ultimate bioweapon
Scourge: The Once and Future Threat of Smallpox.