Comparing data from two vastly different pandemics, with more than a century separating them, is perhaps an impossible task. But, a new analysis published in the journal JAMA Network Open, is suggesting a novel metric for comparing the 1918 Spanish Flu pandemic to our current pandemic, and the conclusion is COVID-19 is just as deadly, possibly even more so.
Between 1918 and 1920 around one third of the world’s population became infected with H1N1 Influenza virus. Tens of millions died, including up to 675,000 in the United States. It was one of the worst pandemics the world had ever seen.
A new study has attempted the perilous task of comparing the current COVID-19 pandemic to the 1918 Spanish Flu. The big challenge of course, is finding an effective frame of reference to compare these two dramatically different events. Directly comparing the virulence of the two viruses is impossible, and the evolution of modern medical science means a number of interventions we have now to save lives were obviously not available 100 years ago.
So, simply comparing deaths, as a proportion of cases, is not useful because it doesn’t truly indicate whether SARS-CoV-2 is a deadlier virus than H1N1. This new analysis, led by Jeremy Faust from Brigham and Women’s Hospital, looked to compare excess deaths in New York City across the first two months of COVID-19, against the same datapoint from NYC in the worst two months of that pandemic.
The analysis calculated 287 deaths per 100,000 people in NYC at the peak of the Spanish Flu pandemic. In comparison, the city saw 202 deaths per 100,000 during the COVID-19 peak in March and April. So the Spanish Flu was clearly more deadly than COVID-19 right? Not exactly …
The research calculated a baseline monthly death rate, averaged over the three years leading up to both pandemic events. Leading up to the Spanish Flu peak in 1918, NYC saw around 100 deaths for every 100,000 residents. More recently that baseline death rate has dropped to around 50 deaths per 100,000, meaning relatively speaking, COVID-19 is at least as deadly as the Spanish Flu.
“…because baseline mortality rates from 2017 to 2019 were less than half that observed from 1914 to 1917 (owing to improvements in hygiene and modern achievements in medicine, public health, and safety), the relative increase during early COVID-19 period was substantially greater than during the peak of the 1918 H1N1 influenza pandemic,” the authors write in the study.
While more people in totality died during the acute initial outbreak of the Spanish Flu in NYC compared to COVID-19 at its worst in March and April, the spike in excess deaths seen earlier this year was higher. Faust suggests this means COVID-19 is at least as bad as the Spanish Flu.
“They’re comparable events in terms of magnitude,’’ says Faust, in an interview with USA Today. “I think maybe we imagine pandemics and plagues and other calamities to be this sort of historical events where the streets are lined with dead bodies and there’s pestilence and filth, but what our numbers show is that what happened in New York was pretty similar to what happened in the greatest modern pandemic.’’
Eric Topol, from the Scripps Research Translational Institute, is suggesting another, more ominous, perspective on these comparative numbers. Speaking to the New York Times, Topol says, taking into account all the modern medical innovations that save lives today, it is concerning that COVID-19 is delivering even similar death rates to the Spanish Flu.
“There was no such thing as an intensive care unit, there was no ventilator, there was nothing,” says Topol. “I mean, they basically had masks and distancing. We have so much more, and yet the mortality is roughly comparable.”
In the conclusion to the latest analysis from Faust and his colleagues, it is suggested the goal of this analysis was to help people contextualize the, “unusual magnitude of the COVID-19 pandemic.” Understanding the significance of the unfolding pandemic is the first step towards working to decrease transmission.
The new analysis was published in the journal JAMA Network Open.
