During the 2021-2022 influenza season, the prevalence of COVID-19 and influenza co-infections was high

Researchers at the University of Missouri School of Medicine found that during the 2021-2022 flu season, the prevalence of COVID-19 co-infections in central Missouri was high, with a monthly co-infection rate of up to 48%
for COVID-19 patients.

The findings come from 462 patients at the University of Missouri Health Care Center who tested positive for COVID-19 and subsequently tested
for the flu.
Of those who tested positive for COVID-19, 33% also tested positive
for influenza.

Senior author Dr Henry Wan, Professor of Molecular Microbiology and Immunology, Veterinary Pathology, Electrical Engineering and Computer Science, said: "Co-infections in our sample peaked at 48% in October 2021, when the Delta variant predominated, reaching its lowest point in January 2022, when the Omicron variant predominated," said Wan who also leads the Next Generation Influenza and Emerging Infectious Diseases Centre and is a principal investigator at the Bond Life Sciences Centre
。

Of the 462 patients infected with COVID-19, 51% carried the Delta variant and 38% carried the Omicron variant
.
People who were infected with the Omicron variant and received at least one flu vaccine during the 2020-2022 flu season are less likely to be infected with both influenza and COVID-19
.
They are also less
likely to be hospitalized.

"Although the effectiveness of influenza vaccines for the 2021-2022 season is low, estimated at less than 16%, our study highlights the importance of flu vaccines because they appear to provide some protection against not only influenza infection, but more importantly, against COVID-19 and flu co-infection
," Wan said.

Future studies involving a wider geographic region and a more diverse population are needed to better understand the overall prevalence of influenza and COVID-19 co-infections and the effectiveness of
COVID-19 and influenza vaccines.

"Testing for and vaccinating
against the influenza and COVID-19 viruses in patients with symptoms of respiratory illness should continue to be encouraged," Wan said.

Virology.
SARS-CoV-2 and influenza co-infection: A cross-sectional study in central Missouri during the 2021–2022 influenza season