By the mid 1960s, Smallpox had been eradicated from Europe and North America, as well as China, Japan and Australia. But it continued to affect 44 countries across Africa, Asia and South America. The World Health Organization was logging 131,000 reported cases of smallpox a year – and estimated the global annual death-toll was a staggering 10,000,000.
In 1966, the WHO decided to embark on what they called an Intensified Ten-Year Smallpox Eradication Programme, despite fears of many (including the WHO’s own Director-General) that such an ambitious endeavour was impossible.
(Right)WHO recognition card showing a child with smallpox, used during the global eradication campaign. © The World Health Organisation The programme was launched in an era of Cold War rivalries, but it attracted remarkable support from both sides of the superpower divide, and showed what could be achieved when the world came together with a single determined purpose (see the module “Global Action”).
By 1972, smallpox was eradicated in Latin America. But in Africa and Asia the task ahead was remained formidable. Local health workers faced immense cultural and logistical challenges, operating in mountains, jungles, and deserts.
Mass vaccination vs containment
Right from the start, the WHO knew that traditional strategies of mass vaccination would not work on a global scale.
Developments in vaccine technology in the 20th century had led to the creation of a freeze-dried vaccine, stable in tropical conditions, and jet injectors could vaccinate 1000 to 1500 people per hour. But even so, mass vaccination was an impossible dream. Vaccinating so many people would require an army of local health workers, and stocks of vaccine couldn’t possible cover the vast and growing populations of the smallpox stricken nations.
Instead, the WHO adopted a strategy of observation and containment. Rewards were offered for sightings of smallpox cases. When an outbreak occurred, local WHO health workers moved in, vaccinating all those in the patients’ immediate circle and the localised population within a proscribed radius from the epicentre of the outbreak. In this way they starved the virus of its human host, extinguishing varioli in pocket after pocket until smallpox, in its natural form, was no more.
(Right) Two local Bangladeshi volunteers analyzing a “Containment Map”, during the smallpox eradication campaign in Bangladesh. © The Centre for Disease Control and Prevention.
Overcoming local obstacles
The eradication was a triumph both for the WHO and for its local health workers, and for the many local groups and national bodies with whom it cooperated. Strategy on the ground was constantly shifting to adapt to local circumstances.
(Right) Bangladeshi volunteers spread the word by rickshaw and megaphone, alerting villagers to rewards on offer for the sighting of smallpox cases. © The Centre for Disease Control and Prevention. In some places – especially on the Indian subcontinent – resistance to vaccination was fierce, especially where local people retained a belief in the gods smallpox. On such occasions, WHO operatives forced compliance with compulsory home searches and forced vaccinations.
But for the most part, the eradication programme found enthusiastic support on the ground. Outbreaks of smallpox were reported, rewards claimed, and containment measures put in place. In district after district – and nation after nation – smallpox was eradicated (see module “The Eradication of Smallpox”).
A world free of smallpox
Two years without a single smallpox case were required to declare an area smallpox-free. After the final cases of the disease in India and Bangladesh, extensive house to house searches were conducted in both countries, three times in India, eight times in Bangladesh. Estimates suggests 98% of the 726,811 towns and villages were searched.
A child being vaccinated in the smallpox eradication campaign in the South Cameroons. © The Centre for Disease Control and Prevention. Two years after the last naturally occurring case of Smallpox, on May 8th 1980, the WHO adopted a resolution which “solemnly declared that the world and its peoples have won freedom from smallpox”.
It was the fulfilment of Jenner’s prophecy made in 1801, and an unprecedented event in human history: the deliberate worldwide eradication of an important human disease.
The excitement at the global success of the eradication programme led many to believe that smallpox was just the first, and that we could take on other diseases in the same way.
But the fact is, at least in part, it was the particular nature of smallpox that enabled the eradication programme to succeed. Smallpox has no reservoir outside the human population – it couldn’t lie dormant in an animal host, or elsewhere. Victims are only contagious only once the disease has become visible – once the rashes have formed – and so with careful observation, smallpox can be contained before serious damage is done. Even given these tremendous advantages, the leader of the WHO eradication programme, Donald Henderson, believes the campaign he coordinated ‘only just succeeded’.
HIV/Aids activists protest outside the Parliament in Cape Town, South Africa, demanding free HIV medication for all who need it. 2003. © Keystone The tragedy is that at the very moment smallpox was eradicated, another disease appeared on the global scene, HIV, or the human immunodeficiency virus. As Elizabeth A. Fenn puts it in her book, “Pox Americana”: “If eradication was a triumph, it was also a punctuation mark. It marked the close of an optimistic era in which public health officials had envisioned the imminent end of infectious disease itself. Already, at the time the eradication of smallpox was announced, the still-unknown and unidentified human immunodeficiency virus (HIV) had begun its silent transit around the world, representing only the deadliest of many new or resistant “emerging” diseases. Thus the elimination of one plague in 1979 was only replaced by the fear of new ones.”
The global struggle against malaria, cholera, HIV, tuberculosis and many other viral diseases continues. To date, the eradication of smallpox remains a unique event in human history.