The impact of influenza vaccination on the clinical severity of influenza among children aged 6 months to 6 years living in the community: a prospective cohort study

Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine

Purpose Evidence on whether influenza vaccination reduces disease severity in children with breakthrough infections in community settings is limited. Materials and Methods This prospective study enrolled 388 children (aged 6 months–6 years) diagnosed with influenza at a community health center in Shenzhen from May 2024 to October 2025. Participants were grouped by vaccination status within the prior year: vaccinated (n=196) and unvaccinated (n=192). Clinical characteristics, healthcare utilization, and outcomes were compared. Results Vaccinated children showed significantly lower peak body temperature (38.81°C±0.58°C vs. 39.03°C±0.64°C), shorter fever duration (2.01±1.21 days vs. 2.45±1.55 days), and fewer symptoms like myalgia and gastrointestinal issues (all p<0.01). They also had fewer outpatient visits, lower outpatient costs, and markedly reduced rates of hospitalization (4.1% vs. 21.9%) and antibiotic use (5.6% vs. 15.1%) (all p<0.05). Conclusion Influenza vaccination could mitigate symptoms, reduce hospitalization and antibiotic use, and lessen the healthcare burden from breakthrough infections.