We have just commemorated the centenary of the Great Flu Pandemic of 1918, which lasted only a few months but claimed 50 million to 100 million lives worldwide, including 675,000 in the United States. That pandemic remains a benchmark, and many commentators have rushed to compare it to the current coronavirus outbreak. What’s most striking about these comparisons, though, is not the similarities between the two episodes, but the distance that medicine has traveled in the intervening century. Whatever happens next, it won’t be a second 1918.
That year, as pandemic influenza ravaged communities as diverse as California and Kolkata, no one knew what was killing them. Theories abounded. Some suggested it was a misalignment of the planets. (That’s what gave us the name influenza, from the Italian word for “influence.”) Others believed the cause was tainted Russian oats, or volcanic eruptions. Microbiologists focused on a bacterium they had discovered decades earlier in the lungs of influenza victims, and called it Bacillus influenza. But they had merely recognized a bacterium that invades lungs already weakened from influenza. Not until 1933 did two British scientists demonstrate that the cause must be a new class of disease, which today we call viruses. Finally, in 1940, the newly invented electron microscope took a picture of the influenza virus, and for the first time in history we could not only name, but also see, the culprit.
The contrast with the coronavirus, which causes the disease COVID-19, could not be greater. From the very start of the outbreak, scientists suspected a virus. Within two weeks, they had identified it as a coronavirus, sequenced its genome, and discovered that the most likely animal hosts were bats. This information, which was published by a Chinese team, was instantly shared across the scientific community, allowing research labs around the world to begin the long and complicated process of understanding the virus, and finding a vaccine and a cure. We may not have beaten the enemy yet, but we certainly know a great deal about him.
The Great Influenza Pandemic of 1918 occurred in the pre-antibiotic era. Although antibiotics do not treat viruses, they do treat the secondary bacterial infections that sometimes follow. These secondary infections cause severe pneumonia, and were likely responsible for most of the deaths in 1918. Back then, there was little to offer. Physicians recommended quinine (not helpful), dry champagne (ditto, though more fun), and phenolphthalein (a cancer-causing laxative). During an earlier outbreak of influenza, in 1916, British military physicians had even tried bloodletting as they treated dying soldiers. When it failed, they suggested it had simply not been tried soon enough in the course of the disease. Patients survived in spite of their doctors.
Today we live in a world that is flooded with antibiotics. And although there is concern that bacteria are becoming ever more resistant to them, antibiotics remain an overwhelmingly powerful tool to treat secondary bacterial pneumonia. Early case reports describe these infections in COVID-19 patients, and we have every reason to believe that for many, though sadly not all, antibiotics will provide a cure.