Study: Combined influenza and COVID-19 vaccines offer best defense for children

As the world moves on from the COVID-19 pandemic, vaccination experts are exploring the efficacy of COVID-19 and influenza vaccines separately, together, and how kids fared with no vaccination at all. The data reveals that one or the other is good, but both are better, according to a new report.

The study was published in Frontiers in Pediatrics in October 2023. Researchers used the health records of more than 17 million children spread across 75 health organizations to investigate vaccination trends, and how children fared throughout influenza and COVID-19 waves based on their vaccination status and other sociodemographic features.

Nearly 14 million children were sickened during the COVID-19 pandemic, but not all of them became severely ill. Less than 2% overall were hospitalized. The team notes that there were no real gender differences, but that younger children and children with higher body mass indexes were among the most likely to become severely ill or require hospitalization.

Specifically, the study team looked at how many children ended up diagnosed with multisystem inflammatory syndrome (MIS-C), a severe complication of these respiratory viruses. Beyond age and health data, the research team also notes that African American and White children were most affected by these infections compared to other ethnic groups.¹

Beyond ethnic and physical characteristics, the team notes that vaccination status perhaps played the largest role in how sick children became during the pandemic and in the immediate period after.

Children who were not vaccinated against COVID-19 and did not receive the influenza vaccine in the year before the pandemic had higher rates of hospitalization, MIS-C diagnosis and even death compared to COVID-19 unvaccinated children who had been previously vaccinated against influenza.

Children who received at least one dose of the COVID-19 vaccine fared a bit better, even if they hadn’t received the influenza vaccine the year prior.

To put a number on this comparison, children who were not vaccinated against either virus had hospitalization rates of 8.4% and MIS-C rates of 0.8% compared to hospitalization rates of less than 6% and MIS-C rates of 0.2% in children were vaccinated against both influenza and COVID-19.¹

The study team concluded that while either vaccine offered some protection, having both vaccines offered the strongest level of protection against hospitalization, severe complications like MIS-C, and death.

Additional research should explore how and why obesity has such an impact on the severity of these respiratory illnesses, according to the report. The team also suggests that the benefit of the influenza and COVID-19 vaccine together could open the door for a combined vaccine in the future.

Reference:

Ali M, Phillips L, Kaelber DC, Bukulmez H. Characteristics of pediatric COVID-19 infections and the impact of influenza and COVID-19 vaccinations during the first two years of the pandemic. Front Pediatr. 2023;11:1046680. Published 2023 Oct 12. doi:10.3389/fped.2023.1046680