COVID is still deadlier than the flu - but the difference is shrinking

Patients hospitalized with COVID-19 were more likely to die than those hospitalized with influenza during the fall and winter of 2023-24, according to an analysis of VA data.

Among more than 11,000 patients hospitalized with one of these illnesses last fall and winter, 5.7% of COVID-19 patients died within 30 days of hospitalization, compared with 4.24% of influenza patients, reported Ziyad Al-Ali, MD, of the VA Medical Center in St. Louis, and colleagues.

After adjusting for variables, the risk of death in people hospitalized with COVID-19 was 35% higher (adjusted HR 1.35; 95% CI 1.10–1.66), the authors detail in a letter in the journal JAMA.

Al-Ali said his group was actually surprised by the results. “We pretty much bought into the public narrative and drank the Kool-Aid like everyone else, thinking that COVID was no longer [worse than the flu], even though... there was no data,” he said. “But now the verdict is clear because we’ve analyzed the data for the 2023-2024 COVID season, and obviously COVID is still more deadly than the flu.”

Additionally, the authors noted that the study results should be considered in light of the fact that the number of hospitalizations due to COVID-19 was nearly twice as high as due to influenza during the 2023-2024 season, according to the CDC's monitoring service. In the study population, nearly three times as many people were hospitalized due to COVID-19 as due to influenza.

However, the results showed that the risk of death in patients hospitalized with COVID-19 was reduced compared to the previous 2022-2023 season. In their 2023 study, using the same database and methods, Al-Ali's group found that in the fall and winter of 2022-2023, COVID was about 60% more lethal than influenza in patients hospitalized for those illnesses.

"We must continue to take COVID seriously," Al-Ali stressed. "I know we are all tired of this pandemic and we are all suffering from pandemic fatigue, but COVID is still a bigger health threat than the flu."

Reassuringly, they found no significant difference in the risk of death among patients hospitalized with COVID-19 before and during the emergence of the JN.1 SARS-CoV-2 variant (adjusted HR 1.07; 95% CI 0.89–1.28), indicating that JN.1 is likely no more severe than other recent variants, they suggested. The JN.1 variant became prevalent beginning in late December 2023.

The study analyzed data from VA electronic health records across all 50 states. Researchers identified people hospitalized with a diagnosis of COVID-19 or influenza between Oct. 1, 2023, and March 27, 2024, or with a positive test two days before or within 10 days of hospitalization. Patients with either condition who were hospitalized for another reason were excluded. The study cohort included 8,625 participants hospitalized with COVID-19 and 2,647 participants hospitalized with seasonal influenza.

After propensity score weighting, the median age of the two cohorts was about 74 years, and 95% were men. About 19% were African American, and 65% were white. About 47% were infected before the emergence of the JN.1 variant. Additionally, of patients hospitalized with COVID-19, about 65% had received three or more COVID-19 vaccinations, but about 15% had not received any vaccinations. About 44% of the study population had been vaccinated against influenza.

Only about 5.3% of people with COVID-19 received outpatient antiviral treatment, such as nirmatrelvir-ritonavir (Paxlovid), molnupiravir (Lagevrio), or remdesivir (Veklury). In contrast, 8% of patients hospitalized with influenza received outpatient oseltamivir (Tamiflu).

The authors noted that the VA study population was older and mostly male, so the results may not generalize to other populations. In addition, causes of death were not examined.