Researchers in Denmark conducted a large-scale evaluation of the disease burdens associated with COVID-19 and influenza. Their conclusion? COVID-19 has a greater impact than influenza, resulting in more hospitalizations and deaths. These findings, they note, emphasize the continued need for a strong public health response.

COVID-19 Exhibits Greater Disease Burden Than Influenza

To compare the disease burden of COVID-19 and influenza, the researchers evaluated data available from Danish health registries from May 16, 2022 to June 7, 2024. The results were published in The Lancet Infectious Diseases. A commentary about the findings was published in the same issue of the journal.

During this period, the risk of hospitalization due to COVID-19 was approximately two times higher than the risk of hospitalization due to influenza. The risk of death was approximately three times higher. The researchers note that these increased risks were greater during the first year of the study period but still were evident during the second year. The risk of mortality, for example, was five times greater for COVID-19 during the first year of the study. That increased risk dropped during the second year, but COVID-19 still had a two and a half times greater risk of mortality than influenza.

COVID-19 Remains A Significant Threat

Infectious disease experts often cite the case fatality rate of an infectious agent as one measure of its disease burden. Simply, the CFR represents the proportion of people diagnosed with an infectious disease who die from the disease.

Five years since the beginning of the COVID-19 pandemic, roughly 780 million confirmed cases of COVID-19 have been reported worldwide, resulting in over 7 million deaths, according to data provided by the World Health Organization. The ratio in the U.S. is similar. About 103 million cases and 1.22 million deaths have been reported. These numbers indicate a CFR of approximately 1%.

This rate is significantly lower than the rates associated with other recent coronavirus outbreaks like SARS (CFR = 11%) and MERS (CFR = 34%). However, the CFR of COVID-19 far exceeds the CFR of seasonal influenza.

The disease burden of COVID-19 certainly has dropped over the course of the pandemic. Various factors most likely have contributed to this change. Most people today possess some degree of natural or vaccine-induced immunity. As a result, rates of severe disease, hospitalization, and death should be lower. But the disease burden remains significant. We must continue our efforts to prevent new infections and develop effective treatments for infected individuals. In their article, Bager et al. note, “These results highlight the continued need for attention and public health efforts to mitigate the impact of SARS-CoV-2.”

Policies Must Align With Empirical Evidence

In the accompanying commentary, Dr. Yan Xie, a researcher at the Washington University School of Medicine, noted that there exists, “a profound disconnect between empirical evidence and public health policy, particularly in vaccine prioritisation strategies.” He added, “Governments must prioritize robust surveillance and monitoring systems, data collection, analysis, and clear communication about the state of infectious threats, including COVID-19’s ongoing impacts.”

When asked to elaborate on these points, Dr. Xie commented, “The disconnect arises primarily from the notion that COVID-19 has become less severe and in the eyes of many an inconsequential infection.”