OBJECTIVES: We aimed at estimating the impact of extending the French influenza vaccination programme from at-risk/elderly (≥65 years) only, to additionally include children (2-17 years). METHODS: A deterministic, age-structured, dynamic transmission model was used to simulate the transmission of influenza in the French population, under the current coverage with the trivalent inactivated vaccine (TIV) in at-risk/elderly individuals (=reference strategy) or after extending the coverage to healthy 2-17 years-old children with an intranasal, quadrivalent live-attenuated influenza vaccine (QLAIV) (=evaluated strategy). The transmission probabilities were determined using between-individuals contact patterns (“Polymod” matrix). Epidemiological, medical resources and costs data were issued by crossing data from literature and French resource-based value scales. The basic reproduction number (R0) of the model was calibrated to the observed numbers of influenza-like illness visits/year and deaths/year. The 10-year, undiscounted, number of symptomatic cases of confirmed influenza and direct medical costs (All-payer) were calculated for the 0-17 (direct effect) and ≥18 years-old (indirect effect). The incremental cost-effectiveness ratio (ICER) was calculated for the total population, using a 4% discount/year. Univariate and probabilistic sensitivity analyses were performed. RESULTS: Model calibration yielded R0=1.27 (assuming 2.3 million visits/year and 1,960 deaths/year). In the 0-17 years-old with 50% QLAIV coverage, the average number of confirmed influenza cases dropped by 865,000/year, averting 58.4% of the cases occurring in the reference strategy and leading to 10-year savings of €374 million. In the ≥18 years-old with unchanged TIV coverage, 1.2 million cases/year of confirmed influenza were averted (-27.6%), yielding additional 10-year savings of €457 million. On average, 613 flu-related deaths were avoided annually. The ICER was €18,000/life-year gained. The evaluated strategy was 98% cost-effective at a €30,000/life-year gained threshold. CONCLUSIONS: The model demonstrated the direct and indirect benefits of protecting healthy children against influenza with QLAIV, on public health and economic outcomes in France.