Eradication of Smallpox

Smallpox, caused by the variola virus, was a highly contagious and deadly disease that plagued humanity for centuries, claiming millions of lives. Edward Jenner's development of the smallpox vaccine in 1796 marked a significant breakthrough in medicine, demonstrating that inoculation with cowpox could prevent smallpox.

In 1967, the World Health Organization (WHO) launched a global campaign to eradicate smallpox through widespread vaccination and surveillance efforts. This initiative led to the last natural case of smallpox being recorded in Somalia in 1977. In 1980, WHO officially declared smallpox eradicated, making it the first and only infectious disease to achieve this milestone. This achievement stands as one of the most remarkable successes in public health history, highlighting the power of vaccination and coordinated international efforts in combating infectious diseases.

Smallpox presents with early symptoms such as high fever, fatigue, and severe back pain, occasionally accompanied by abdominal pain and vomiting. Within days, a distinctive rash emerges, starting on the face and hands before spreading to the body. The rash consists of fluid-filled bumps that progress to pus-filled lesions and eventually crust over. Additionally, lesions can form in the nose and mouth, leading to ulcers.

Transmission occurs via infective droplets during close contact with symptomatic individuals or through contaminated clothing and bedding. The disease has an incubation period of 7–17 days and becomes contagious once fever develops, persisting until all scabs have fallen off. With a fatality rate of up to 30%, smallpox posed a significant threat to public health before its eradication.

The WHO Smallpox Secretariat oversees smallpox eradication efforts, coordinating research on vaccines and antivirals. Post-eradication, it manages emergency preparedness and conducts biosafety inspections. It supports preserving smallpox history and documenting lessons learned. A debate arose over destroying remaining variola virus stocks; in 1996, Member States decided to destroy most, retaining only small samples for research. This research is overseen by the Advisory Committee.