What to know
- Although smallpox has been eradicated, it is possible that variola virus could be used in a biological attack.
- There is no immediate, direct threat of a bioterrorist attack using smallpox. No bioterrorist attack using smallpox has happened in modern times.
- If an attack were to occur in the United States, public health authorities would find out when the first sick person seeks treatment.
- CDC and state and local public health authorities would then put response plans in place.
About bioterrorism and smallpox
Thanks to a successful worldwide vaccination effort in the 20th century, smallpox has been wiped out. No one has gotten smallpox naturally since 1977. However, it is possible that variola virus (the virus that causes smallpox) could be used in a biological attack (an intentional release of viruses, bacteria, or other germs that can sicken or kill people, livestock, or crops). Public health authorities prepare for a possible but unlikely biological attack that uses smallpox as a weapon.
Why smallpox is a concern
Throughout history, though, some people have used smallpox to their advantage by deliberately infecting their enemies with the disease.
Public health authorities are concerned about smallpox because it is a serious—even deadly—disease. Today, there are only two labs in the world that are approved to have the smallpox virus for research: the Centers for Disease Control and Prevention (CDC) in the United States and the Russian State Centre for Research on Virology and Biotechnology in the Russian Federation. There is credible concern that in the past some countries made the virus into weapons, which may have fallen into the hands of terrorists or other people with criminal intentions.
The last natural outbreak of smallpox in the United States happened in 1949. The last naturally spread case in the entire world happened in 1977. The World Health Assembly declared smallpox eradicated in 1980. Even a single confirmed case of smallpox today would be considered an emergency.
If the virus that causes smallpox were used in a bioterrorist attack, people who come into contact with the virus would be at risk of getting sick. By 1972, the smallpox vaccine was no longer given routinely in the United States. As a result, most people born in the United States after 1972 have not been vaccinated against the disease. Some people have been vaccinated through the military or because they were part of Smallpox Response Teams that were formed after the 9/11 terrorist attacks. These vaccination efforts are part of the larger plan to prepare for a bioterrorist attack. However, the vaccine does not give lifelong immunity, and people who have been vaccinated against smallpox before may still need to be revaccinated in a smallpox emergency.
What an attack would look like
Most likely, if smallpox is released into the United States as a bioterrorist attack, public health authorities will find out once the first person sick with the disease goes to a hospital for treatment of an unknown illness. Doctors will examine the person and use tools developed by CDC to figure out if the person's signs and symptoms are similar to those of smallpox. If doctors suspect the person has smallpox, they will care for the person and isolate them in the hospital so that others do not come in contact with the smallpox virus. The medical staff at the hospital will contact local public health authorities to let them know they have a patient who might have smallpox.
Local public health authorities would then alert public health officials at the state and federal level, such as CDC, to help diagnose the disease. If experts confirm the illness is smallpox, then CDC, along with state and local public health authorities, will put into place their plans to respond to a bioterrorist attack with smallpox.
How CDC would respond
Detection
Smallpox is caused by a virus, which is too tiny to be seen by the eye without a powerful microscope. If a smallpox bioterrorist attack happens, public health authorities would find out once people started getting sick. Most likely, sick individuals will go to their primary care providers or their local emergency rooms. The medical staff would try to rule out other more common illnesses first.
If after ruling out other diseases the medical staff still suspects smallpox, they would contact their local public health authorities and CDC for help to confirm or rule out the disease. CDC laboratories would make the final confirmation of smallpox.
CDC's response
A single, confirmed case of smallpox would be a public health emergency and CDC would respond immediately. CDC has worked with other federal, state, and local agencies and authorities to plan how each would respond individually and how they would all respond together in a smallpox emergency.
CDC has a detailed plan to protect people if a smallpox emergency were to happen. Smallpox was wiped out through specific and deliberate disease control actions, like vaccination. In an emergency, CDC will take these actions again.
Some of the things CDC would do in an emergency:
- Coordinate activities within CDC and with other partners through the Emergency Operations Center.
- Communicate with the public to let them know where to go for care or how to protect themselves from getting sick.
- Guide health care providers, hospitals, health departments, and others on how to respond.
- Work with the Laboratory Response Network (LRN) to test samples from sick people.
- Send out field staff to talk to people who are sick with smallpox and those who were in close contact with them.
- Ship out vaccines and other supplies from the Strategic National Stockpile (SNS) to states and other locations where needed.