COVID vs Flu: Which Is Deadlier?

COVID-19 remains deadlier than influenza in severe cases requiring hospitalization, a new study shows.

People who were hospitalized with Omicron COVID-19 infections were 54% more likely to die, compared to people who were hospitalized with the flu, Swiss researchers found.

The results of the study continue to debunk an earlier belief from the start of the pandemic that the flu was the more dangerous of the two respiratory viruses. Researchers noted that the deadliness of COVID-19 compared to flu persisted “despite virus evolution and improved management strategies.”

The study was published this week in JAMA Network Open and included 5,212 patients in  Switzerland hospitalized with COVID-19 or the flu. All the COVID patients were infected with the Omicron variant and hospitalized between Jan. 15, 2022, and March 15, 2022. Flu data included cases from January 2018 to March 15, 2022.

Overall, 7% of COVID-19 patients died, compared to 4.4% of flu patients. Researchers noted that the death rate for hospitalized COVID patients had declined since their previous study, which was conducted during the first COVID wave in the first half of 2020. At that time, the death rate of hospitalized COVID patients was 12.8%.

Since then, 98% of the Swiss population has been vaccinated. “Vaccination still plays a significant role regarding the main outcome,” the authors concluded, since a secondary analysis in this most recent study showed that unvaccinated COVID patients were twice as likely to die compared to flu patients.

“Our results demonstrate that COVID-19 still cannot simply be compared with influenza,” they wrote.

While the death rate among COVID patients was significantly higher, there was no difference in the rate that COVID or flu patients were admitted to the intensive care unit, which was around 8%.

A limitation of the study was that all the COVID cases did not have laboratory testing to confirm the Omicron variant. However, study authors noted that Omicron accounted for at least 95% of cases during the time the patients were hospitalized. The authors stated that they were confident that their results were not biased by the potential for other variants being included in the data.

Source: JAMA Network Open: “Hospital Outcomes of Community-Acquired SARS-CoV-2 Omicron Variant Infection Compared With Influenza Infection in Switzerland.”