Gdoc/Admin
Data InsightsSmallpox declined gradually, until the WHO coordinated the global effort to eradicate it

Smallpox declined gradually, until the WHO coordinated the global effort to eradicate it

The image presents a line graph showing the number of countries where smallpox was endemic from 1920 to 1980. There are five colored lines representing different regions: Africa, Asia, the Americas, Europe, and Oceania. 

The y-axis indicates the number of countries, ranging from 0 to 50, while the x-axis marks the years from 1920 to 1980. Each region's line trends downward, reflecting a decline in endemic countries over the years. Significant events are marked with dashed vertical lines: in 1959, the WHO resolved to aim for eradication; in 1967, an intensified eradication campaign began; 1977 marks the last recorded case; and in 1980, smallpox was declared eradicated.

A note at the bottom specifies that the precise year of elimination in Oceania is only known for Australia (1917) and New Zealand (1914). Additionally, data sources are cited as Fenner, Henderson, Arita, Jezek, and Ladnyi (1988) and the graph is attributed to Saloni Dattani, licensed under CC-BY. The source of the data is Our World in Data, which focuses on research and measures against global issues.

In 1796, Edward Jenner developed the world’s first vaccine against smallpox. As it was refined and widely adopted, many countries in Europe and North America, the Soviet Union, and island nations eliminated smallpox through national vaccination programs.

But in the mid-20th century, the disease remained widespread across Africa and Asia, infecting tens of millions every year.

Before the World Health Organization (WHO) committed to eradication in 1959, few believed it was possible, given the failures of other eradication efforts like malaria. But smallpox had no animal reservoir, clear symptoms, and there was an effective, low-cost vaccine.

By 1967, the WHO intensified the eradication campaign with more funding. The strategy focused on “ring vaccination” — containing outbreaks by vaccinating people around each case — and embedding the work within local health programs.

As the chart shows, this approach worked swiftly: within a decade, the number of endemic countries fell to zero. Smallpox was officially declared eradicated in 1980, two centuries after Jenner’s discovery. It’s a lasting triumph of science and cooperation.

Read more on our page on smallpox

Our latest Data Insights

See all Data Insights

Get Data Insights delivered to your inbox

Receive an email from us when we publish a Data Insight (every few days).

By subscribing you are agreeing to the terms of our privacy policy.