In the midst of the resurging Covid 19 pandemic, reading how we went through the previous great pandemic — the 1918 Spanish Flu AKA H1N1 flu — is illuminating.

How deadly was the 1918 Influenza Pandemic? About one third of the people at that time ( 500 million) became infected, and at least 10% of them died. Whereas the current raging Covid 19 mostly kills elderly people, the 1918 influenza hit hardest at the people younger than 5 years old, 20~40 years old and above 65 years old. As a result life expectancy was slashed significantly; the life expectancy in the US was slashed by 12 years. We don’t know about other countries ( especially other countries) as we didn’t have complete statistics of them ( or even now).

Covid 19 is nowhere nearly as deadly, in terms of both the infection rate and the mortality rate, partly because we now know better– we quarantine early, take protective measures like wearing masks and washing hands, have better intervention method, and also, I think, partly because Covid 19 is a whole different beast than 1918 Influenza. Covid 19 is kind to the young but not to the old, and therefore the reduction in life expectancy is somewhat minimized.

The vaccine for Covid 19 was developed and approved for use in (recorded) one year time, raising the hope that we can get over the pandemic “pretty soon” — in one or two years time when the majority of the population is vaccinated. But we never did manage to develop a vaccine for 1918 Influenza. In fact, at that time we weren’t even really sure of the cause of the Influenza– was it virus, or just bacteria? Today we know that the virus is the main culprit, and bacteria infection only came later when the victim was already significantly weakened. But at that time, we just didn’t know, and hence lots of time and resources were spent on fixing the wrong issues.

Unlike today whereby the secondary bacteria infection kills in significantly less proportion ( well, at least in hospitals with proper care units), one can imagine that back in 1918 bacteria infection was also a major contributing factor to the mortality. Penicillin, the precursor to antibiotics that treat bacteria infection wasn’t invented until 1928.

1918 would not be the last time we see a pandemic, in the year 1957 we saw a new H2N2 virus bursting onto the scene, resulted in 1957~1958 pandemics and killed about 1.1 million people. 10 years later, a new virus H3N2 came around that killed also around million people. A more recent example is the 2009 H1N1 virus, which by the name of it you can probably guess that the virus is also made of the previous strain but with some modification.

As years go by, the virus “mellows out” and becomes less deadly, and not solely because we know how to deal with it better. In order for virus to spread it needs to latch on to as many hosts as possible, but then it also has the nasty habit of killing them in the process. So in the end it will just deprive itself of the living environment. So for the virus to continue surviving, it must “learn” how to co-live with us better. So it works both ways: no only we know how to deal with a virus better throughout the time, the virus also knows how to live with us better. It’s a mutual relationship.

The Great Influenza is a fascinating book: it tells us how and where the 1918 Influenza was developed and spread, and our response towards it. It turns out that policy decision makers of that day was not too much different from today– both downplayed the virality and the mortality of the virus in order to keep economy functioning; “It’s just influenza”, a dismissive remark that was uttered frequently in 1918 as well as in 2020. Such attitude led to delay in taking necessary precautions and contributed to the spread of the virus. In 1918 World War I was still raging, and the US government used this excuse to censor the press in the name of maintaining public order, a situation not too unlike how China authorities handled the initially outbreak in Wuhan.

The book also entertains an intriguing question: did the Influenza cause World War 2, albeit in an indirect way? On the surface this seems like a preposterous question; How can a virus cause people to go mad and kill each other in large number only 25 years later after its first appearance? But let’s just phrase the question slightly differently, World War 2 was directly related to Hitler, can the virus cause the rise of Hitler?


This is how the chain of reasoning goes. Hitler was elected in 1930s at the time Germany was steeped in depression and a deep sense of humiliation, resulted from the unfair treaty signed after the defeat in World War I. Now why on earth would the Allies of World War I, the victorious party consisting of France, Britain and the US would impose such a harsh term on the defeated party, the Central Powers, of which Germany is bearing the most of the grunt? Didn’t they know that such a loop sided and harsh treaty was only fanning the instability and hence laying the seeds for a second World War? The author speculates that after the then US president, President Woodrow, caught a flu during the treaty negotiation, he was “never the same against mentally and physically.” Previously, Wilson had insisted that the treaty must represent “peace without victory” and would not give in to the harsh terms French President Georges Clemenceau wanted to impose on the Germans. But after getting the flu, Wilson “yielded to Clemenceau everything of significance Clemenceau wanted”.  

We can’t rewind back the history and run its course again, this time controlling the effect of virus. But this is definitely interesting to ponder about this possibility.

As for this Covid 19, will it cause further world war? Again we don’t know, but it might already have helped us averting the third one, by getting rid of Donald Trump.