Effectiveness of inactivated and live-attenuated influenza vaccines in children during the 2025–2026 influenza season with genetically distinct influenza A and B viruses
Vaccine·
- DOI
- 10.1016/j.vaccine.2026.128869
- PMID
- 42349133
- PMCID
- —
- OpenAlex
- W7165924829
- Study type
- Journal article
- Publisher
- Elsevier BV
- Article type
- journal-article
- Integrity
- current
Why this research matters now
These outcomes reinforce the utility of existing immunization protocols for youth amid evolving viral genetics, highlighting the need for longitudinal tracking as alternative delivery methods gain traction.
Structured evidence summary
Research question
The investigation assesses how well two pediatric influenza formulations perform during a season characterized by divergent viral subtypes.
Study design
Researchers utilized a test-negative methodology across sixteen medical centers to compare outcomes between confirmed cases and uninfected controls.
Population and setting
The cohort consisted of pediatric patients presenting with fever requiring hospital admission and subsequent outpatient diagnostic screening in Japan.
Main findings
Statistical modeling indicated moderate efficacy for the injectable formulation and higher efficacy for the nasal spray against type A pathogens, while neither preparation demonstrated meaningful defense against type B infections.
Public-health relevance
These outcomes reinforce the utility of existing immunization protocols for youth amid evolving viral genetics, highlighting the need for longitudinal tracking as alternative delivery methods gain traction.
Important limitations
The evaluation acknowledges a constrained number of subjects receiving the attenuated option, which limits statistical power for direct comparisons. Additionally, the reliance on a test-negative framework introduces potential selection biases inherent to healthcare-seeking behavior.
GIDS interpretation
This peer-reviewed report serves as a static reference point for historical seasonal performance metrics, aiding literature discovery without implying alignment with active monitoring networks.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 12 auditable classifier relationships to diseases, places, topics, and study design.