Flu Vaccine Protected Over Two-Thirds of European Children, Study Finds

Influenza vaccination protected more than two-thirds of European children against medically attended flu infections during the 2022/2023 and 2023/2024 seasons, according to a study published in Pediatrics.

The research analyzed data from over 19,000 pediatric patients across nine European countries, finding that vaccine effectiveness ranged from 57% to 83% in the first season and increased to between 71% and 92% in the second season, depending on the virus subtype.

Protection was strongest against influenza B and H1N1 strains, while effectiveness remained lower for the H3N2 subtype, consistent with patterns observed in previous flu seasons.

Younger children generally experienced higher vaccine effectiveness compared to older children, particularly against H1N1 and influenza B viruses, though protection against H3N2 varied by age group and season.

Researchers confirmed influenza infection using real-time PCR testing and verified vaccination status through health records or guardian reports, considering only those vaccinated at least two weeks before symptom onset as protected.

The study’s findings support ongoing public health efforts to increase influenza vaccine uptake among children and continue monitoring effectiveness trends to guide immunization strategies across Europe.