Lessons from the eradication of smallpox

Vox has a nice and short read out on the battle against smallpox, and lessons we might learn today from how and where the battle was waged, at what costs, and with what effects.

But for all that the world has lost in the last few years, the history of infectious disease has a grim message: It could have been even worse. That appalling death toll resulted even though the coronavirus kills only about 0.7 percent of the people it infects. Imagine instead that it killed 30 percent — and that it would take centuries, instead of months, to develop a vaccine against it. And imagine that instead of being deadliest in the elderly, it was deadliest for young children.
That’s smallpox.


My notes after having read the article:

  1. Smallpox is estimated to have killed between 300 million to 500 million people in the 20th century alone
  2. We still do not have an effective treatment against smallpox
  3. There are two different viruses that cause smallpox: variola major and variola minor
  4. We no longer need to explain R0 to anybody, thanks to covid, but this point is staggering: it had an infectiousness of between 5 to 7, and a mortality rate of 30%.
  5. “In China, as early as the 15th century, healthy people deliberately breathed smallpox scabs through their noses and contracted a milder version of the disease. Between 0.5 percent and 2 percent died from such self-inoculation, but this represented a significant improvement on the 30 percent mortality rate of the disease itself.”
    What a horrible lottery to play. Would you play this lottery? This, by the way, is one of the many reasons why learning statistics and probability is worth your time.
  6. Learn more about Edward Jenner.
  7. We have better ways of shipping vaccines across the world these days, but what a story this is!
    “Spain especially struggled to reach its colonies in Central and South America, so in 1803, health officials in the country devised a radical new method for distributing the vaccine abroad: orphan boys.
    The plan involved putting two dozen Spanish orphans on a ship. Right before they left for the colonies, a doctor would give two of them cowpox. After nine or 10 days at sea, the sores on their arms would be nice and ripe. A team of doctors onboard would lance the sores, and scratch the fluid into the arms of two more boys. Nine or 10 days later, once those boys developed sores, a third pair would receive fluid, and so on. (The boys were infected in pairs as backup, just in case one’s sore broke too soon.) Overall, with good management and a bit of luck, the ship would arrive in the Americas when the last pair of orphans still had sores to lance. The doctors could then hop off the ship and start vaccinating people.”
  8. Institutions matter:
    “It was not until the 1950s that a truly global eradication effort began to appear within reach, thanks to new postwar international institutions. The World Health Organization (WHO), founded in 1948, led the charge and provided a framework for countries that were not always on friendly terms to collaborate on global health efforts.”
  9. Culture matters:
    “Efforts by the British Empire to conduct a smallpox vaccination program in India made less progress, due in large part to mistrust by the locals of the colonial government.”
  10. Science matters:
    ” “There was no shortage of people telling [the people involved in the eradication effort] that their effort was futile and they were hurting their career chances,” former CDC director William Foege wrote in his 2011 book House on Fire about the smallpox eradication effort.
    But other advances had brought it within reach. Needle technology had improved, with new bifurcated needles making it possible to use less vaccine. Overseas travel improved, which made it easier to ship vaccines and get public health workers where they were most needed, and provided impetus for worldwide eradication as it made it more likely that a smallpox outbreak anywhere in the world could spread.”

As always, read the whole article. I’ll quote here the concluding paragraph from the piece, and I’d urge you to reflect on it:

The devastation of Covid-19 has hopefully made us aware of the work public health experts and epidemiologists do, the crucial role of worldwide coordination and disease surveillance programs (which are still underfunded), and the horrors that diseases can wreak when we can’t control them.
We have to do better. The history of the fight against smallpox proves that we’re capable of it.