Smallpox

History of Smallpox

Smallpox harmed people for thousands of years. Evidence of smallpox appears in ancient records. Later, outbreaks often happened during times of trade, exploration, and travel.

Early efforts to control smallpox used a process called “variolation.” People who had never had smallpox were purposely exposed to the variola virus, usually through a scratch on the person's arm. The person would get sick, but the disease was usually not as severe as natural smallpox.

In 1796, Doctor Edward Jenner noticed that people who were exposed to a mild disease called cowpox were protected from smallpox. This method was safer than variolation. After more scientific experiments, this process became known as vaccination. Over time, this method was widely adopted. The vaccinia virus eventually replaced cowpox in the smallpox vaccine.

By the 1950's and 1960's, scientists and public health experts had the tools the eliminate smallpox.

The smallpox vaccine worked well, and countries around the world worked together to stop outbreaks quickly. Smallpox was officially declared eradicated in 1980.

Signs and Symptoms

Smallpox symptoms began with a stage called the prodrome, which lasted two to four days. This stage included:

• Fever
• Fatigue, or tiredness
• Headache and body aches
• Sometimes stomach pain and vomiting

After the prodrome, a rash appeared. Sores often started in the mouth and on the face, then they spread to the rest of the body. People were most contagious during this time, when the rash was spreading. 

The sores changed over time. They started as small red spots, then filled with thick fluid. Later, they became raised bumps under the skin called pustules. Finally, the sores formed scabs, which later fell off. A person with smallpox was no longer contagious once every scab had fallen off.

Many survivors had permanent scars on their faces and bodies from the rash. Some lost their sight if the sores affected their eyes.

Smallpox was often deadly, especially for pregnant women, infants and adults ages 30 and older.

Vaccination and Prevention

Vaccines help protect us from dangerous diseases like smallpox. Thanks to worldwide vaccination efforts, smallpox was eradicated. 

Most people today do not need the smallpox vaccine. It is not part of routine childhood or adult vaccination schedules. Only certain high-risk groups may need it, such as some members of the military and people who work with pox viruses in laboratories.

The risk of smallpox being released on purpose or by accident is believed to be low. Even so, the United States keeps a large supply of smallpox vaccines and a strong emergency response plan.