Flu Shots Reduced COVID-19 Infection Rates and Severity
The American Journal of Infectious Diseases published a major article: Impact of the Influenza Vaccine on COVID-19 Infection Rates and Severity. These researchers stated on February 22, 2021, 'Influenza vaccination is associated with decreased positive COVID-19 testing and improved clinical outcomes and should be promoted to reduce the burden of COVID-19.'
This study found the odds of testing positive for COVID-19 were reduced in patients who received an influenza vaccine by 24%.
And, influenza-vaccinated patients testing positive for COVID-19 were less likely to require hospitalization or mechanical ventilation and had a shorter hospital length of stay.
These researchers concluded by saying, 'The results of our study indicate that influenza vaccination presents no harmful effect on COVID-19 susceptibility or increased disease severity, and points to a possible association between the vaccine and decreased risk of COVID-19 and improved clinical outcomes. While our descriptive study cannot discern mechanisms, a hypothetical yet plausible immunologic mechanism that could explain the apparent protective effects of influenza vaccine against COVID-19 is a process called trained immunity.'
'Until the COVID-19 vaccine becomes widely available, the influenza vaccine should be promoted to reduce the burden of disease during this pandemic.'
This was an electronic medical records-based retrospective cohort study. Future prospective studies are needed to establish a causal relationship between the influenza vaccine and COVID-19 susceptibility and severity.
No conflict of interest and no industry relationship was disclosed by Anna Conlon, Ph.D., Carmel Ashur, M.D. MS; Laraine Washer, M.D.; Kim A. Eagle, M.D.; Marion A. Hofmann Bowman, M.D.