Smallpox, a highly contagious and often deadly disease, was declared eradicated by the World Health Organization in 1980 through a worldwide immunization campaign.

The vaccine that helped destroy smallpox in the 1970s could once again protect the public, but the risks involved with the vaccine could outweigh the benefits for some people.

People with AIDS, organ transplants and those with weakened immune systems from cancer and chemotherapy could have reactions to the vaccine that would cause serious complications that could lead death, according to the Mayo Clinic Web site.

"I think smallpox is a real threat," said Dennis Paulk, a pharmacist at Desoto Discount Drugs in Hernando. "I have mixed emotions about vaccinating everyone, but I believe we should be ahead of the game."

Smallpox is a disfiguring and often deadly disease caused by the variola virus and is transmitted mainly from face to face contact when a person coughs or talks. It can also be spread through the ventilation system in a building and, less likely, through infected clothing or bed linen. One-third of its victims are killed.

"I worry about vaccinating the kids and then them having problems later on," Paulk said.

Complications from the vaccine can occur when the blister that forms after the shot has been scratched onto the skin is touched and then can get into the bloodstream from other open areas on the body (like a scratch or open wound.)

Smallpox symptoms begin to appear 12 to 14 days after a person has been infected. After an incubation period of seven to 17 days, flu-like symptoms begin, including fever, bodily discomfort, headache, severe fatigue and back pain.

Then flat red spots (lesions) that characterize smallpox appear. These lesions fill with pus that cause the skin to separate from its layers. The pain is intense, and the lesions leave deep, pitted scars. Most smallpox patients die during the second week of the disease.

According to the Centers of Disease Control and Prevention if a healthy American population was given the smallpox vaccine, at least one or two of every 1 million people who have never been vaccinated would have fatal complications.

This statistic does not take into account the unhealthy people and the other complications that could result.

The last U.S. smallpox case was reported in 1949 and the world in Somalia in 1977. On paper, smallpox only exists in Russia and at the CDC in Atlanta.

Many people believe that after the Soviet Union fell, their stockpile of clandestine smallpox, made in secret labs, could have fallen into other hands.

The United States currently has enough smallpox vaccines to protect everyone in case of an emergency, according to the CDC.

Smallpox has been labeled a Category A agent by the CDC, along with anthrax, bubonic plague, botulism and others because it has the ability to become a threat to the public and it has moderate-to-high potential for large-scale dissemination.