The coronavirus pandemic has taken the world by storm. Schools, jobs and businesses have been shut down since early March, and the numbers of cases and deaths have only increased since. But, this unprecedented time can be compared to another pandemic from over 100 years ago. 

The Spanish flu, also known as the 1918 flu pandemic, was an unusually deadly influenza pandemic caused by the H1N1 influenza A virus. Lasting about 15 months from summer 1918 to early summer 1919, it infected 500 million people — about a third of the world’s population at the time. The death toll may have been anything from 17 to 50 million people and possibly as high as 100 million, making it one of the deadliest pandemics in human history. 

Most influenza outbreaks disproportionately kill the very young and the very old, with a higher survival rate for those in between, but the Spanish flu pandemic resulted in a higher than expected mortality rate for young adults. Scientists offer several possible explanations for the high mortality rate of the 1918 influenza pandemic. Some analyses have shown the virus to be particularly deadly because it triggers a cytokine storm, which ravages the stronger immune system of young adults. Instead, malnourishment, overcrowded medical camps and hospitals and poor hygiene, all exacerbated by the recent war, promoted a bacterial superinfection. This superinfection killed most of the victims, although it was a somewhat prolonged process. 

Tara Smith is an epidemiologist, science communicator and a professor at the Kent State University College of Public Health, studying zoonotic infections. When comparing the 1918 pandemic to COVID-19, Smith said there are several similarities between the two viruses.

The Spanish flu and the coronavirus are both considered “novel,” which is to say, they are so new nobody in either era had any immunity to them. There were no vaccines for the Spanish flu, there are currently no vaccines for COVID-19 and both viruses started overseas. One marked difference between the two is that the most affected groups in the 1918 pandemic were otherwise healthy adults between the ages of 20 to 40. Mortality was also higher in people younger than five years of age and those 65 and older, but both viruses also have their differences, which may be hard to identify. 

“You know, we can’t really tell the difference between the two viruses,” Smith said. “They are fairly similar; however, we have never seen this strain before, so we cannot predict how many people it can still kill, when there will be a second wave or if we can find a vaccine for it soon.”

Considering the potential severity of COVID-19, most people’s main concern is protecting themselves against the virus.

“Basic public health intervention: hand-washing, social distancing and wearing your face masks, can help tremendously in keeping yourself and others safe,” Smith, who is also on the reopening committee for Kent State, said. “Although I ultimately decided for students to return [to campus], returning to normal concerns me. The virus is far from gone, and we still need to be really cautious about spreading the virus. Even though we’re missing people, is it really worth the risk?”

Contact Ciana White at [email protected].