Long COVID Severity May Be Similar To Flu: Study

Long Covid appears to manifest as a post-viral syndrome of no greater incidence or severity than seasonal influenza, finds new research. However, the similarity observed is only valid for people who are vaccinated, according to the study, being presented at this year's European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) held in Copenhagen, Denmark between April 15 and 18.

The study by researchers at Queensland Health in Australia suggests that despite the similarity of clinical outcomes after Covid-19 and influenza, long Covid’s impact on public health systems is likely to stem from the volume of those infected with SARS-CoV-2, rather than the severity of long Covid symptoms.

During concurrent waves of Omicron and influenza that occurred in mid-2022, 2,195 adults diagnosed with Covid-19 and 951 adults diagnosed with influenza were followed for 12 weeks and asked about ongoing symptoms and functional impairment using a questionnaire delivered by SMS link to a survey.

At the time, more than 90 percent of the population of Queensland had been vaccinated against Covid-19. Of those diagnosed with Omicron, a fifth (21 percent) reported ongoing symptoms at 12 weeks and 4 percent reported having moderate to severe functional limitations in everyday life.

Similarly, around a fifth (23 percent) of adults diagnosed with influenza reported ongoing symptoms and 4 percent reported moderate to severe functional limitations.

The analysis found no evidence to suggest that adults with Omicron were more likely to have ongoing symptoms or moderate to severe functional limitations at 12 weeks after their diagnosis than adults who had influenza.

Interestingly, the analyses suggest that younger age groups and non-indigenous populations were more likely to report moderate to severe functional limitations after influenza than Omicron.

The study also has several limitations including that it was observational and can’t prove causation and it can’t rule out the possibility that other unmeasured factors such as underlying illness and influenza vaccination status may have influenced the results.