Can the Flu Shot Help with COVID?

Although COVID-19 vaccines are becoming more widely available and the vaccine rollout is increasing in speed and doses administered, many people are still waiting to become eligible to receive their doses. Because of the nature of vaccine trials, no vaccine has yet been approved for use in children. However, a recent study has indicated that children receiving their seasonal flu shot might experience milder coronavirus symptoms if they did become infected with the novel coronavirus. How were these results obtained, and what might this mean?

Why Children Can’t Get Vaccines Yet

For most vaccines, the most common strategy is known as an “age de-escalation strategy,” where trials begin with those aged 18 and older, and slowly move down to younger and younger participants. This helps ensure safety and efficacy with all age groups.

Trials for the coronavirus vaccine for children as young as 12 are just getting started and will continue to move down to younger and younger children over time. Thanks to results from a new American study, there is some evidence that receiving a flu vaccine (which is already approved for young children) could make a severe reaction to COVID-19 less likely.

The Study

Conducted by researchers with the University of Missouri School of Medicine, this study observed 905 children under the age of 20 that had been diagnosed with a COVID-19 infection. The results, published on February 4, 2021, in the peer-reviewed medical journal Cureus, indicated that children who had received their seasonal flu vaccine had a lower incidence of experiencing symptoms with a coronavirus infection. Researchers note that this is likely due to a known phenomenon called “virus interference,” which can occur even with an inactive virus, such as the kind used in the flu vaccine. Virus interference is when the growth of one virus is inhibited by a previous viral infection. In this case, the inactivated virus used in the seasonal flu vaccine has likely caused the growth of the coronavirus to be inhibited when children contract it.

Future Research

Based on the results of this study, researchers note that it will be important to explore this possible connection between the symptoms of COVID-19 and vaccinations in a larger study covering multiple races and geographic areas. Studying the pediatric population and how it experiences COVID-19 is crucial, because children are known to play an important role in influencing how viruses are transmitted.