How did the Spanish Flu Pandemic End?
The 1918 Flu Pandemic, also known as the Spanish Flu (a misleading name, since it most likely started in Kansas), was one of the most deadly pandemics ever to strike humankind.
Naturally, during our pandemic, we seek to understand more about past pandemics — but the example of the 1918 Flu Pandemic is quite an extreme one. It had a death toll of up to 50 million people, more than there are cases of COVID-19.
Though it is an extreme example, it can’t be discarded as unlikely. The Spanish Flu was most deadly in its second wave, and COVID-19 remains in its first.
For more moderate examples, we should look to pandemics that might strike more resemblance to what we see with COVID-19, like the 1957 Influenza Pandemic (global death toll: estimated 1–2 million), or the 1968 Flu Pandemic (global death toll: estimated 1 million).
The one thing all of these pandemics have in common is that they all lasted for about a year.
Though the Spanish Flu Pandemic lasted a year and a half, having started in January 1918 and mostly ended by June 1919, most deaths took place in a 16 week period from September to December 1918. October was the month with the highest death toll.
The Spanish Flu hit in four waves — the first was mild, the second was the deadliest, the third was deadlier than the first, and the fourth was minor. The second wave was what made the pandemic so devastating.
But how did the pandemic end?
The end of a pandemic is hard to pinpoint, but we can safely say that things started going back to normal by late 1918.
How it ended is, surprisingly, quite a mystery. The number of cases diminished quickly at the end of the second wave, and from then on, the cases that did appear were nowhere as deadly or as disrupting as they had once been.
From mid-October to mid-November 1918, the weekly death toll of the Spanish Flu in Philadelphia went from about 4,600 to about nothing.
The most mind-boggling part is that nobody knows how it faded so quickly. There are many theories, one of which is most likely right, yes, but they are all still very much disputed.
Pandemics vary wildly from each other, and it is hard to make any definitive conclusions from past pandemics that apply to ours.
However, there are things we can learn from past pandemics — the effectiveness of locking down and social distancing, for example. Perhaps one could even say that it is likely that our pandemic will last about a year since most pandemics seem to run their course in this time frame.
But having a likely time frame for COVID-19 should not give us a sense of complacency — we are still facing a major pandemic, and if we really want to learn lessons from the past, one of them is that a lot of people can die in a very short time frame.
