Local Expert: Smallpox Hard To Weaponize
Posted November 21, 2001
RALEIGH, NC — Smallpox is a virus that creates red lesions on the skin similar to chicken pox. The virus attacks internal organs, causing organ failure and usually death.
Dr. David Weber, an infectious disease expert at UNC, says smallpox is "the doomsday of all biologic agents ... because, in my mind, if this was released anywhere in the world it would be severely difficult to contain."
The last case of smallpox in the United States was in 1972. Worldwide, it was declared eradicated in 1980. But the virus still exists.
The U.S. has a stockpile at the Centers for Disease Control in Atlanta. Russia also has a hefty supply in at least one location. It has been rumored that Iraq and North Korea have the virus.
Weber says that even though smallpox is highly contagious, it would be hard to weaponize, unlike anthrax, which is a bacteria and can thrive anywhere.
"A virus has to grow in a living cell, which means you need a cell, which is more difficult to maintain and more difficult to grow in large amounts," he says.
The government and CDC believe the threat is significant enough to restart production of the smallpox vaccine.
Until the late 1960s, receiving the smallpox vaccine was routine. But as the virus disappeared from the world, so did the need for vaccinations.
The U.S. has about 15 million doses of vaccine on reserve. Studies are under way to see how effective it is and if it can be diluted to stretch out the supply.
It would take up to four years to produce enough vaccine for everyone in the country, and the vaccine can have significant side effects.
In 1968, 15 million doses of smallpox vaccine were given in the United States and nine people died from it. About 600 people became severely ill from the vaccine.
Weber believes the government could decide to vaccinate those people most at risk and give mass vaccinations if and where an outbreak occurs.
"Besides being effective given before exposure to smallpox, it's also effective given the first four days after exposure," he says.
Most people are not protected from previously administered smallpox immunizations. It is estimated that 50 percent of the U.S. population is not immunized against smallpox. No one under 30 has immunity. Of those who did receive the smallpox vaccine, the immunity only lasts 3-5 years. That group may have some partial immunity, but local experts says this is by no means "protective."