The Opposing Thumb

An opinionated digit leafs through the biological literature
Science Policy

Smallpox: Extinction or Containment?

On October 12th, 1977, Ali Maow Malin, a hospital cook and vaccination field worker in Somalia, drove two children with smallpox symptoms to a clinic. One of them, a girl named Habiba Nur Ali succumbed to the illness. Habiba was six years old and she was the last human being to die of naturally acquired smallpox. Two years later, the World Health Organization would declare smallpox to be the first eradicated disease. By some estimates, it had killed more people than all other infectious diseases combined. In its abbreviated 20th century alone, smallpox had killed some 300 million people.

Variola virus, the smallpox agent, has vanished from the wild, via a deliberate act of planned extinction. However, in an arrangement typical of the Cold War, vials of viable virus were preserved in two World Health Organization authorized repositories at the State Research Center of Virology and Biotechnology in Koltsovo, Russia (the then USSR) and at the Centers for Disease Control in the United States. The samples exist for research and should a new stock be required to reinitiate vaccine production. But of course, the vials also present a real danger. Research stocks are not innocuous- in fact, the last known smallpox death resulted from a laboratory infection at the University of Birmingham, UK. 

Inger Damon and colleagues in PLOS Pathogens discuss the pros and cons of maintaining history’s deadliest infectious agent alive in the freezer. They make a strong case for the need to continue developing diagnostic and therapeutic approaches to smallpox, in the process granting variola a stay of execution. The reappearance in human populations of the original virus would almost certainly require either catastrophic error or a deliberate criminal act, neither of which can, of course, be entirely excluded.  But we also need to understand better the intimate relationship between variola and our little twig on the primate tree. This intimacy was at the root of successful eradication- variola had nowhere to hide once effective surveillance, quarantine and vaccination procedures were deployed. Here is Hugh Pennington on one of the last natural outbreaks: “And even if smallpox were released, we know how to control it. In India in 1974 there were 188,003 cases. In January 1975 there were 1010 and in March, 84. The last ever case in India was in a 30-year-old Bangladeshi beggar who lived on the station platform at Karimganj in Assam. She developed her rash on 26 May 1975.”

Impressive stuff, no doubt, and the story of smallpox is something to remember when your favorite celebrity suddenly shifts his or her interests from Kabbalah studies to anti-vaccination campaigns. But variola is only one member of a large family, the orthopoxviruses, and its relatives frequently infect our relatives. Rare but significant cases of various monkeypox viruses jumping host to humans are known- though none have ever started a full-blown contagion cycle. About one third of infected people died from smallpox- and we do not have any real reason to hope that mortality would be lower today. An effective treatment for those who contract the disease was never developed. Prevention was, and remains, the only solution. Given all the possibilities, OT has to agree with Damon et al that “the research agenda with live variola virus is not yet finished and that significant gaps still remain”.

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The smallpox virus (Image: CDC Public Health Image Library)

Ali Malin was infected by the smallpox virus while driving Habiba and her family. He became ill five days later. Malin had, when he was younger, been afraid of the smallpox shot and had not been vaccinated. Luckily, he made a full recovery and continued to work on vaccination drives in his native Somalia. Once smallpox was defeated, Malin became engaged in the effort to eliminate polio. He told the BBC “Somalia was the last country with smallpox. I wanted to help ensure that we would not be the last with polio too”. The last person naturally infected with smallpox, Malin died in 2013, six years after the last Somali polio case .

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Ali Maow Malin (Image: World Health Organization).

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