What the Spanish Flu teaches us about Corona Virus

And other observations and speculations about COVID-19

The Spanish Flu did not start in Spain nor was it especially severe in that nation, but unlike its neighbors, it had a free press. Spain was a rare neutral nation surrounded by a world at war with itself. To maintain morale, the warring nations — France, US, UK, Germany, etc. — censored news of the outbreak while the Spanish press reported it freely, thus giving the impression it was the hardest hit and possibly the source.

The pandemic was unusual in another important way which may have contributed to its astonishing mortality rate which killed far more people than all the combined fighting of World War I. Around 5% of the world population is believed to have been killed, with the current population that would translate into about 390 million deaths today. Why was that flu so deadly? One theory that stands out is that the war led us to react to the disease contrary to how we normally would.

Viruses mutate and evolve and over time they tend to become less deadly. In 1918, it was exactly the opposite. In normal times when a virus manifests different strains, some milder and some more severe, the milder ones will almost always win and become dominant. This is logical. When you are very sick then you tend to travel very little. You don’t socialize or work, you stay home. If you have a mild illness you travel much more and thus encounter many more potential hosts to spread the virus to. Over time the mild version dominates. In 1918, the front lines of the war were mostly stationary and those that were mildly ill would stay put. Those that had more severe illnesses would be moved away from the front line to facilities spread out around the world. In an unusual anomaly, the sicker you were, the more contact you had with others.

Happily, we avoided WWIII in January (How long ago that seems now, right?). However, countries are prohibiting some healthy people from traveling while simultaneously flying sick people from various parts of the world ‘home.’ That’s good politics, but bad practice.

Map courtesy of Johns Hopkins University https://www.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423467b48e9ecf6

We don’t know why seasonal flu abates in the Spring

The greatest fear is the fear of the unknown and that’s a big part of what’s happening right now — we simply don’t know what will happen because this is new. The seasonal flu is something that we grew up with. It can be devastating, but at least it’s familiar. We understand it. Or do we?

One of the big questions around COVID-19 is whether it will naturally slow in the Spring and if so if it will come back in the Fall. The only honest answer to that is that we don’t know. Seasonal flu and other corona viruses do, so it’s logical to expect COVID-19 to follow that trend. Problem is, we don’t know why they do, so we can’t be sure that COVID-19 will have that in common. There are a lot of very logical and reasonable theories — about humidity, temperature, UV light, etc. — but no definitive proof that explains exactly why this happens. For example, experiments have demonstrated that the virus is better able to survive in drier air and humidity tends to drop in the winter and even more so within indoor heated spaces. That would suggest places like Arizona would be significantly more susceptible than somewhere along the coast and that is not true. There is still a lot we don’t understand, and we’ve been studying this for a century.

Looking at a world map COVID-19 outbreaks are all in northern countries that have been in winter. Tropical nations such as the Philippines or Indonesia have significantly fewer cases and that is promising. Both those nations have had recent increases though which are worth keeping an eye on as a possible early indicator to how the virus may act as Winter yields to Spring and Summer.