Comparing the 1918 Spanish Influenza and the 2020 COVID-19 pandemics

While the effects of COVID-19 and the Spanish influenza of 1918 are similar in terms of public response, the viruses themselves are quite different. While it’s true that both viruses are “novel” – meaning they were so new that no one had immunity to them – they are markedly different in terms of genetic makeup, symptoms, incubation period, and fatality rate. The Spanish flu was a result of the H1N1 virus that originated in birds, while COVID-19 is the result of the coronavirus - which is thought to have originated in either bats or pangolins. This is the current “best guess;” as of today, experts have not been able to pinpoint the exact origin of COVID-19.

The Spanish flu and COVID-19 also have different symptoms and onset patterns, though the end results of the two appear similar. Persons infected with Spanish flu began experiencing symptoms almost immediately, typically in one to two days following exposure. Initial symptoms included headache and fatigue on the first day, followed by dry cough, loss of appetite, stomach problems, and on the second day, excessive sweating and chills. If the infection progressed (and it often did), it spread to the respiratory organs, causing pneumonia and other respiratory complications. These were determined to be the main causes of death. Those infected with COVID-19 have experienced a more gradual progression of symptoms, and a sizable portion of its victims have no symptoms at all. The most common symptoms of COVID-19 are fever, dry cough, and difficulty breathing. Individuals who have succumbed to the virus were reported to have died from respiratory complications like pneumonia. In this way, the final nail in the coffin for sufferers of both viruses has been respiratory issues.

Finally, the fatality rate for both viruses differs vastly, perhaps due to differences in population size. Spanish flu had a fatality rate of about 2%, with the population in 1918 approaching 1.8 billion. The group most vulnerable to Spanish flu were healthy adults ages 20 to 40, and mortality was unusually high. Experts project that COVID-19 has a fatality rate of 1%, which is still ten times higher than seasonal influenza. Mortality is high in older adults over 65 or individuals with compromised immune systems. This isn’t to say that these groups are the only ones who should take caution, however.

Guest blogger Rachel Seitz