Flu vaccine may not increase Covid-19 risk: Study

Researchers have found that receiving the influenza vaccine does not increase a person's risk for contracting Covid-19 or worsen associated morbidity or mortality. Published in the Journal of Clinical and Translational Science, the study shows the flu vaccine is the single most important intervention to help stay healthy this fall and winter.

For the findings, the research team analysed more than 13,000 patients tested for Covid-19 at Cleveland Clinic in the US, between early March and mid-April of this year. "Our findings suggest that we should proceed as usual with our vaccination strategy for global influenza this flu season," said study author Joe Zein from Cleveland Clinic in the US.

"Getting the annual flu vaccine remains the best safeguard against the influenza virus--both for yourself and the people around you," Zein added.

Comparing those who had received unadjuvanted influenza vaccines in the fall or winter of 2019 (4,138 patients) against those who did not receive the vaccine (9,082 patients) revealed that influenza vaccination was not associated with increased Covid-19 incidence or disease severity, including risk for hospitalization, admission to the intensive care unit or mortality.

Since much is still unknown about the possible outcomes of concurrent Covid-19 and influenza infection, researchers and clinicians believe that the population's adherence to widespread and early flu vaccination will help to mitigate the risk of simultaneous viral infections and epidemics/pandemics.

"We have already seen the stress that Covid-19 can put on our hospitals and resources," Zein said.

"While we're not yet sure how flu season will affect Covid-19 susceptibility and infections, we strongly advise people to get their influenza vaccines, both for their individual health and the collective health of our care systems," Zein added.

According to the researchers, seasonal flu activity is unpredictable, and otherwise healthy people are hospitalized due to serious respiratory infection each year.

"This year, it's even more important to receive the flu vaccination to help prevent a twindemic of flu and Covid-19," the study authors wrote.