While some still had their doubts, a new study from Canada shows that covid-19 can indeed be more deadly than the flu. In fact, the research found that the risk of death from covid-19 was 3.5 times higher than for influenza.
From "It's just like the flu," to "Flu kills more people than covid-19," assertions like this have been all over social media in recent months, suggesting that part of the population is still skeptical about severe forms of the virus that began disrupting our lives a year ago. So are they right? Not according to researchers in Canada, who found covid-19 to be more deadly than seasonal influenza in a recent study.
Published in the Canadian Medical Association Journal ( CMAJ ), the study compared hospitalizations for influenza between November 1, 2019, and June 30, 2020, in seven large hospitals in Toronto and Mississauga. This included all patients admitted to medical services or intensive care units (ICUs) for influenza or covid-19. In total, during that period, there were 783 hospitalizations for flu in 763 unique patients, compared to 1,027 hospitalizations for covid-19 in 972 unique patients.
"We can now say definitively that covid-19 is much more severe than seasonal influenza," says Dr. Amol Verma, St. Michael's Hospital, Unity Health Toronto, and the University of Toronto. "Patients admitted to hospital in Ontario with covid-19 had a 3.5 times greater risk of death, 1.5 times greater use of the ICU, and 1.5 times longer hospital stays than patients admitted with influenza."
Older adults aren't the only ones at risk of serious illness
Another common preconception partially addressed by the study is that older people actually aren't the only ones affected by severe forms of covid-19. The study notably found that people younger than 50 accounted for 24% of ICU admissions.
"Many people believe that covid-19 mainly affects older people," continues Dr. Verma. "It is true that covid-19 affects older adults most severely. We found that among adults over 75 years who were hospitalized with covid-19, nearly 40% died in hospital. But it can also cause very serious illness in younger adults. Adults under 50 accounted for 20% of all covid-19 hospitalizations in the first wave of the pandemic. Nearly 1 in 3 adults younger than 50 hospitalized with covid-19 required intensive care, and nearly 1 in 10 required an unplanned readmission to hospital after discharge."
One explanation discussed by the researchers is that, beyond the severity of the illness, people currently have low levels of immunity against covid-19 compared to influenza, which may magnify the phenomenon. "Hopefully, the severity of covid-19 will decrease over time as people are vaccinated against the virus and more effective treatments are identified. There is, unfortunately, also the possibility that variants of the virus could be even more severe," the study's lead author concludes.