HEALTH

The 1918 Influenza

1918 CE

History · Contemporary · Holocene · Meghalayan

In the last year of the First World War, an influenza virus of avian origin twice circled the globe, sparing no country, and killed against the usual pattern: hardest among adults in their twenties and thirties. Estimates of the dead range from 17 to 100 million. The virus itself was not recovered until eight decades later, its genome read from the preserved lungs of its victims, and once rebuilt it proved tens of thousands of times more virulent in primates than seasonal flu.

Why it matters

Every influenza pandemic since descends from it: the 1918 H1N1 founded the lineages that still circulate and still kill each winter, in a pandemic era that has never closed. It also set the worst case against which pandemic preparedness is measured, and it is no closed chapter: why the virus killed young adults in such numbers, and how many it killed in all, are questions a century has not settled.

Dating & uncertainty

The pandemic's waves ran from early 1918 to 1919. Its toll is the disputed part: 50 to 100 million deaths in the most cited estimates, revised down to about 17 million by a 2018 reanalysis of mortality registers, a gap of three to six times over what were, on any count, the deadliest weeks of the modern era. Where the virus first spread among people is unsettled too: America is the likelier candidate, though a European origin has also been argued.

Sources

1. Taubenberger et al. (2019), Cold Spring Harbor Perspectives in Medicine · The 1918 influenza pandemic and its legacydoi:10.1101/cshperspect.a038695
2. Spreeuwenberg et al. (2018), American Journal of Epidemiology · Reassessing the global mortality burden of the 1918 influenza pandemicdoi:10.1093/aje/kwy191
3. Berche (2022), Presse Médicale · The Spanish fludoi:10.1016/j.lpm.2022.104127

Our species’ history as one day

23:59:3029.6 s before midnight

if the 315,000 years of Homo sapiens were compressed into a single day