A LARGE observational study has found that cell-based quadrivalent inactivated influenza (QIVc) offered significantly better protection for children compared to the traditional egg-based version (QIVe).
Using USA electronic health records and claims data from the 2022–23 influenza season, researchers identified children aged 6 months–17 years who received either QIVc or QIVe. A test-negative design was applied to compare vaccine effectiveness against laboratory-confirmed, medically attended influenza, adjusting for age, sex, comorbidities, race, and vaccination timing.
Among 3.3 million children, 603,827 received QIVc and 2,727,322 received QIVe. Relative vaccine effectiveness of QIVc versus QIVe was 14.8% (95% CI: 8.3–20.8) in children aged 6 months–8 years and 11.0% (95% CI: 2.7–18.6) in children aged 9–17 years. Protection from QIVc was consistent across age groups and influenza virus subtypes, including influenza A(H3N2) and B lineages. The study also found similar safety profiles between the vaccines.
These data, based on a very large paediatric cohort, suggest that cell-based influenza vaccines provide improved protection over egg-based formulations. The results may support preferential recommendations for QIVc in future influenza seasons.
Reference
Haag M et al. Superior effectiveness of cell-based versus egg-based quadrivalent influenza vaccines in preventing test-confirmed influenza across paediatric populations during the 2023-24 influenza season in the United States. Abstract 2288. ESPID Annual Meeting, 26-30 May, 2025.
