Lessons From the Past: COVID-19 & the 1918 Flu

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Lessons From the Past: COVID-19 & the 1918 Flu

Science often looks to the future: finding the next cure, creating the next vaccine, and predicting the next outbreak. However, looking back in history can sometimes be just as useful. In this blog, we’ll explore the similarities and differences between the 1918 Flu and COVID-19. 

Sometimes referred to as the Spanish Flu, the 1918 Flu had a deadly impact on the U.S. population and on the world. First identified in Spain in early 1918, it eventually killed about 675,000 people in the U.S. and around 50 million people worldwide. (That’s about 10 million more than the number of deaths caused by World War I.) Over the past two years, COVID-19 has also had a fatal impact on people everywhere: just over 1 million people have died from COVID-19 in the U.S. and about 6.6 million have lost their lives to the disease around the world. 

Comparing Lives Lost 1918 Spanish Flu to COVID-19

If the world is more populated now, why have fewer people lost their lives to COVID-19 than from the 1918 Flu? To answer this, we need to consider a couple key things.

  • The ability to vaccinate
  • Public health support
And That’s Science!

Medical researchers have made big strides since 1918. Sickle cell disease (SCD) had just been discovered and now, one hundred years later, we are starting to talk about curative therapies. Between 1918 and when COVID-19 first hit in 2020, researchers had been researching how flus change and spread for over one hundred years specifically because they knew that another pandemic would happen. So, what other advances have been made since then?

  1. Vaccines – While COVID-19 seemed to come out of nowhere, the science behind the COVID-19 vaccines had already been studied for decades. Whether it was the mRNA vaccine (Pfizer & Moderna) or the vector vaccine (J&J/Janssen), scientists already had most of the information they needed to make the vaccine; all that was left was to add the missing ingredient of the actual disease. There was no vaccine for the 1918 Flu, meaning there was a lot less protection against the disease. With COVID-19, due to scientific advances, increased funding for drug development, and prioritization of research, we were able to receive safe and effective COVID-19 vaccinations within a year of the pandemic’s beginning.
  2. Public Health Support – Government health systems were not as comprehensive in 1918 as they are now. Most of the public health support for the 1918 Flu came from charitable organizations. The government did provide some direction such as limiting or preventing social gatherings during the worst parts of the Flu, teaching individuals how to self-quarantine, and recommending that the individuals wear masks while in public. Government health systems have become more capable, especially with funding directed to research and drug development for the pandemic.
Two Pandemics

picture showing masks in both 1918 flu and covid-19 pandemics

While the 1918 Flu and COVID-19 are entirely different viruses, there are some similarities that helped us prepare for COVID-19 a little better.

  • The 1918 Flu also had variants and “waves.” It’s a little difficult to know exactly since researchers weren’t able to track cases like we do today, but researchers believe that the 1918 Flu had three or four waves, the second of which caused two-thirds of all deaths. COVID-19 has also come in waves as variants evolve and the virus mutates, with later variants being more contagious or more severe. This is one of the main reasons it’s so important to continue watching patterns and assume that COVID-19 isn’t done yet.
  • The symptoms of the 1918 Flu were similar to some symptoms of COVID-19 variants. Mainly, fever, fatigue, and chills. However, later variants of the 1918 Flu were known for affecting the lungs by filling them with fluid, while COVID-19 mainly causes inflammation in the lungs. Because of lessons learned from the 1918 flu and other flus, we know that identifying symptoms through changing variants is crucial for catching infections early.
  • Messaging matters. When it comes to communicating ever-changing public health situations, the words you use matter. Guidelines about best practices, social distancing, wearing masks, washing hands, and other safety measures need to be carefully written to avoid the possibility of misinterpreting them. With so much confusion around, it is important that the leading health authorities are able to agree on a message and address any changes together. 
What’s Next?

After learning about the 1918 Flu, it’s logical to ask, “Well, what happened to it? Where did it go?” The answer is that it never truly went away. After mutating and moving through different variants and waves, the 1918 Flu eventually became what we know today as the seasonal flu. But, at what point does a pandemic become endemic? At what point do we decide that a virus doesn’t pose as big of a threat anymore? Here are the things we look for:

  1. Truly being able to predict the number of cases. No more surprises, no more big waves!
  2. Increased vaccination levels. Without a majority of the population vaccinated, variants have more room to grow and change.
  3. Reduced hospitalizations. When hospitals can focus on non-COVID patients for a long period of time, this might signal the pandemic is becoming less severe.
That’s All, Folks

At the end of the day, viruses and pandemics take a big toll on individuals, families, and communities across the world. We often feel like we are just slightly behind them and can’t quite keep up. What is important is that we learn from each one in order to protect ourselves even better against future public health crises like the 1918 Flu and the COVID-19 Pandemic. 



BioSpace (2021), “COVID-19 and the Spanish Flu – Drawing Comparisons”

Liang et al., (2021), “COVID-19: A Comparison to the 1918 Influenza and How We Can Defeat It”

Navarro (2021), “People Gave Up on Flu Pandemic Measures a Century Ago When They Tired of Them – and Paid a Price”

CDC (2022), “COVID Data Tracker Weekly Review”

BBC (2022), “Covid map: Coronavirus cases, deaths, vaccinations by country”


Published October 2022

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