Should every American get a smallpox vaccine, if they want it? The answer is not at least, that's the recommendation of scientists who set vaccine policy in the United States. The scientists say the threat of smallpox being re-introduced as a terrorist weapon is low, but, now zero. Offering mass vaccinations is risky side effects range from swelling to encephalitis, which is a brain inflammation and even death. And today there are about 40 million people with compromised immune systems who are at particularly high risk, a group that didn't exist when the vaccine was in routine use back in the early 70's. "What has changed is that we have more people living today who have altered immune systems, they have been survivors of cancer, they have organ transplants, people with HIV AIDS," said Dr. Harold Margoli, Senior Advisor for Smallpox Preparedness at the Centers for Disease Control. Scientists say the smallpox vaccine is the single most dangerous vaccine because of its possible side effects, yet the advisors are recommending it for some 10 to 20 thousand people. The new recommendation is to vaccinate designated smallpox response teams in every state, made up of medical professionals ranging from doctors, nurses, lab workers and disease investigators, as well as medical personnel at designated hospitals. These vaccinated teams would be responsible for patient contact and care in the event of an outbreak. Health officials want to reassure the public if there is an outbreak, vaccine could get to those who need it quickly. "Could get in 12 hours and plan by July," said Drl Julie Gerberding, Acting Deputy Director of the Centers for Disease Control. Vaccinations were discontinued in the 70's because it was believed the virus was wiped from the face of the earth. The exception, two known stockpiles, one at the CDC in Atlanta and the other in Russia, but, scientists fear it could have gotten into the wrong hands and developed into a terror weapon. The vaccine panel's recommendations are not final, they'll be reviewed by the head of the CDC and HHS Secretary Tommy Thompson. The advice of the vaccine panel is usually taken and a final decision could come in a matter of weeks.