Researchers from the University of Missouri School of Medicine have discovered that children who receive a seasonal flu shot are less likely to suffer symptoms from a COVID-19 infection. The finding comes from a review of more than 900 children diagnosed with COVID-19 in 2020.
"It is known that the growth of one virus can be inhibited by a previous viral infection," said Anjali Patwardhan, MD, professor of pediatric rheumatology and child health. "This phenomenon is called virus interference, and it can occur even when the first virus invader is an inactivated virus, such as the case with the flu vaccine."
Patwardhan reviewed records from 905 pediatric patients diagnosed with COVID-19 between February and August 2020 to determine each patient's influenza vaccination history. She discovered the COVID-19 positive children who received the influenza vaccine in the current flu season had lower odds of experiencing symptoms, respiratory problems or severe disease. She also found that children with COVID-19 who received the pneumococcal vaccine also had lower odds of experiencing symptomatic disease.
"Research on the pediatric population is critical because children play a significant role in influencing viral transmission," Patwardhan said. "Understanding the relationship and co-existence of other viruses alongside COVID-19 and knowing the vaccination status of the pediatric patient may help in deploying the right strategies to get the best outcomes."
Patwardhan said it will also be important to explore the connection between vaccinations and COVID-19 symptoms in a larger geographical-multiracial study.
"Based on these findings, we hypothesize that the higher incidence of COVID-19 in minority populations may also reflect their low vaccination rate apart from other health inequalities," Patwardhan said.
Patwardhan's co-author is MU School of Medicine colleague Adrienne Ohler, PhD, associate research professor. Their study, "The Flu Vaccination May Have a Protective Effect on The Course of COVID-19 in the Pediatric Population: When Does Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-Cov-2) Meet Influenza," was recently published in the journal Cureus.
The authors declare they have received no financial support for this study and report no conflicts of interest.