John M. Barry is the author of “The Great Influenza: The Story of the Deadliest Pandemic in History” and distinguished scholar at the Tulane University School of Public Health and Tropical Medicine
Are there any lessons that can be extracted from this landscape? And does the course of the 1918 pandemic hold any lessons for today?
To answer the last question first, the 1918 pandemic began in the spring with an intermittent first wave no deadlier than ordinary influenza, then seemed to disappear. A more contagious and more lethal variant caused the deadly second wave, and then it also seemed to disappear. In March 1919, another variant sparked a third wave much less deadly than the second wave but more lethal than seasonal influenza. First wave illness protected against the second wave, but neither first nor second wave infection protected against the third wave variant. Further mutations, combined with an improved ability of the immune system to respond, helped turn the virus into an ordinary seasonal influenza — until it was replaced by the 1957 pandemic influenza virus.
Covid-19 was never going to disappear, but there is a reasonable chance that it will follow the 1918 precedent and become an endemic influenza-like illness that kills — serious enough, to be sure — and will require vaccine updates but will not require shutdowns. That would be the best case.
In terms of social, cultural and economic impacts, however, 1918 is not a precedent. The first wave, especially in the United States, was so mild it passed without notice, and no city took any public health action. During the second wave, most cities closed schools, theaters and saloons, and some required masks. But one of the biggest differences between the 1918 pandemic and this one is duration. The 1918 disease usually affected a given community for about six to eight weeks, and restrictions generally lasted only three to five weeks — too short a period for any permanent impact on behavior.
Since the disease disappeared abruptly, society returned to pre-pandemic normal quickly. The third wave hit many cities — though, not all — but no one knew it was coming, so it didn’t affect behaviors, and few places reinstituted restrictions for it.