Sean Illing
Is the coronavirus the closest thing you’ve seen to the 1918 influenza pandemic in your lifetime?
John M. Barry
Nothing else even begins to approach it. At the beginning of the 2009 H1N1 outbreak, there were real fears that it could be bad, but of course it turned out to be fairly mild. If it weren’t for molecular biology, it would never have been noticed at all. So nothing we’ve seen since 1918 even comes close to what’s happening. If this is merely a once-in-a-generation virus, we’ll be lucky.
Sean Illing
How is our situation today different from the situation we faced in 1918?
John M. Barry
The biggest difference is the target demographic. In 1918, the overwhelming majority of people who died were 18 to 45. Maybe two-thirds of the deaths were roughly in that age group. Back in 1918, well over 90 percent of the excess mortality was in people younger than 65. So obviously the elderly in 1918 had experienced a mild virus in their youth that was close enough to the 1918 virus that they had a lot of protection against it from natural immunity.
Another difference is the incubation rate. Influenza’s average incubation rate was two days, almost never longer than four. The average for the coronavirus is more than twice as long and can stretch quite a bit longer than that, which is both a good and bad thing. The good thing is it allows time to contact, trace, isolate, and things like that, which was almost impossible during the influenza epidemic. The bad thing is that that means this virus may stretch out over a much longer period of time and infect more people. It seems to be considerably more contagious than influenza.
Here’s one positive difference: Despite the contagiousness of this, the case fatality rate seems much lower than the 1918 influenza. The fatality rate in 1918, in the West at least, was about 2 percent. In other parts of the world it was much, much higher. Something like 7 percent of Iran’s entire population died. Perhaps as much as 5 percent of Mexico’s population died. [Author’s note: There’s some scholarly debate about the actual fatality rate of the 1918 flu.]
That’s how we ended up with 50 to 100 million total deaths in 1918.
https://www.vox.com/coronavirus-cov...irus-covid-19-spanish-flu-pandemic-john-barry