The government panel that sets U.S. vaccine policy began two days of meetings Wednesday to decide whether smallpox shots should be offered to the public because of the risk of a bioterrorist attack.
The vaccine is currently offered only to lab workers who handle the deadly virus. But health officials are considering whether more people should get vaccinated as a precaution.
Smallpox was declared eradicated more than two decades ago, and the virus is known to exist in only two places: a government lab in Atlanta and a similar one in Russia. But experts fear it could fall into terrorist hands.
The Advisory Committee on Immunization Practices is meeting in Atlanta to weigh the risks of a bioterrorist attack against the dangerous side effects of the vaccine, which can include brain damage and even death.
The panel is expected to make its recommendation Thursday. A decision would rest with the Centers for Disease Control and Prevention and Health and Human Services Secretary Tommy Thompson.
On Wednesday, smallpox experts made presentations to the committee, trying to guess how an outbreak might spread in the United States.
Dr. Mike Lane, a consultant to CDC's National Immunization Program, said he believes widespread media attention and public concern would help health officials track down people at risk of exposure in an outbreak.
Health officials are extremely wary of offering vaccinations to all Americans because the vaccine can cause severe side effects, especially in children and people with immune diseases. If the entire U.S. population were vaccinated, hundreds of people could die from the side effects.