The two-year anniversary of the COVID-19 pandemic came and went without much fanfare, thanks to a lull in cases and deaths, and the start of a war in Ukraine that has grabbed the world's attention.

But for medical historians who led an exhaustive study of the 1918 influenza pandemic, the recent milestone offers a chance to look back on the parallels, and differences, in how the nation responded to both massive infectious threats.

Howard Markel M.D., Ph.D., director of the University of Michigan Medical School's Center for the History of Medicine, along with the center's assistant director Alexander Navarro, Ph.D., led the team that compiled evidence about the impact of different cities' responses to the 1918 flu.

Their work, done for the Centers for Disease Control and Prevention, led to the creation of the online Influenza Encyclopedia of historical articles and images, and to studies that helped shape the "flatten the curve" approach that became famous in the first days of the COVID-19 pandemic.

"It amazes me how much we learned from our nation's experience in 1918 and then put into practice in the spring of 2020, as states and local communities implemented a slate of non-pharmaceutical interventions, or NPI, in an attempt to slow the spread of COVID, 'flatten the curve' of cases, and buy the nation time for the development and distribution of vaccines," Navarro said. "I was pleasantly surprised that, despite some pushback, initial compliance seemed to be fairly high."

But the success of early efforts when the pandemic was concentrated in major metropolitan areas led to pushback from people in less-affected areas, which persisted even when the pandemic spread to their regions.

That's not without historical precedent, Navarro says.

"There was certainly pushback to public health orders in 1918 as well, especially when it came to mask mandates, but overall it was much less vociferous, much less organized, and almost completely non-partisan. And this was at a time when death from infectious disease was a much greater part of daily life for Americans, when the etiology and epidemiology of influenza was not well understood, and when there were no effective drug therapies or vaccines for influenza."

The nature of the public health and political leadership in different cities in 1918 and 1919 shaped the outcomes for their populations, the U-M researchers found. And the same was true in 2020, 2021 and the most recent wave in early 2022.

"With COVID, there is no doubt that we could have done much better as a nation," Navarro said. "Our public health communication and policies have often lacked clarity and focus. Our polity is fractured, impacting our ability to enact solid, science-based public health policies."

The way Americans get their information about infectious threats has changed a lot in a century, of course. Printed newspapers, often many in every city, were the main source in the early 1900s – and they relied heavily on statements from elected and public health officials who were looked upon as trusted sources.   

"Today, Americans get their information from a bevy of sources, some of them trustworthy but many of them not," Navarro said. "Unlike in the Progressive Era, as it was called, where there was a general belief that trust should be put in experts, today many of us are distrustful of government, suspicious of our leaders, and cynical about the motivations of the scientific and medical communities." That has contributed to resistance to, or just disregarding of, measures informed by evolving research on the coronavirus.

Markel notes another parallel with the 1918-1919 pandemic: the potential of war to exacerbate the spread of disease.

Between the movement of troops and the rapid displacement of civilians from conflict zones, the events in Ukraine and surrounding countries since late February could fan the flames of the pandemic.

Markel wrote about this topic in a recent column for PBS Newshour.

"No one has any real idea of how the virus may be spreading now," he wrote, noting that data from just before the Russian invasion began showed that case rates and hospitalizations were already high, and vaccination rates low, in both countries.

That doesn't mean that the soldiers and refugees in eastern Europe right now are doomed to repeat what their forerunners in World War I did, he wrote.

"Unlike our current era, nobody knew much about virology at all back in 1918, and didn't know exactly what caused the flu," he wrote. "Scientists had a better hand on bacteriology, but many experts incorrectly thought influenza was caused by the bacterium Haemophilus influenzae.

"They had no medications yet that would work against bacteria – no antibiotics, let alone antivirals, that could have helped in the pandemic," he continued. "There were no intravenous fluids, respirators or intensive care units; nurses and doctors were in short supply; and medical care was more a form of warehousing these young men and women than what we would expect today. Working at these overcrowded base hospitals, let alone finding yourself in one, was a nightmare."

Markel cites the work of Victor C. Vaughan, M.D., the U-M Medical School dean of the early 20th Century who investigated the ravages of influenza on American soldiers for the Army. The close and open living quarters of barracks, undersupply of medical personnel, poor nutrition and sanitation for troops, and lack of treatments, helped the virus rip through a young healthy population.

Then, as now, "it is safe to say that no one wins if the conflict helps spread the coronavirus," Markel wrote.

Even as the war grips the world's attention, Navarro reflects on how lessons from a century ago, and the past two years, will be needed in the future.

"From the 1918 experience, we learned that good public health policy makes for better public health outcomes," he said. "The lesson from our COVID-19 experience is that a divided nation can make good public health policy very difficult to implement and maintain.  As the world grapples with climate change and as the global population increases, we will likely see a rise in the number of zoonotic spillover events. Any one of these could easily become the next pandemic. Are we prepared for that?"

Like Podcasts? Add the Michigan Medicine News Break on iTunes, Google Podcasts or anywhere you listen to podcasts.