{
  "abstract": "Background: Seasonal influenza causes substantial morbidity and mortality among older adults in South Korea despite high vaccination coverage. The MF59-adjuvanted trivalent influenza vaccine (aTIV) has shown superior immunogenicity in older populations, but its economic value within the Korean National Immunization Program (NIP) has not been evaluated using a dynamic transmission model that captures indirect protection. This study evaluated the budget impact of introducing aTIV into the Korean NIP for adults aged ≥65 years.\n\nMethods: We developed an age-structured dynamic compartmental model to simulate seasonal influenza transmission in South Korea, allowing estimation of both direct and indirect protection effects. From the healthcare payer perspective and over a single influenza season, we performed a budget impact analysis complemented by a cost–benefit comparison of avoided medical costs against incremental vaccination expenditures. Two aTIV strategies were compared against standard quadrivalent influenza vaccine (QIV) within the NIP framework: Strategy I (aTIV for adults aged ≥75 years) and Strategy II (aTIV for all adults aged ≥65 years). Deterministic one-way sensitivity analyses examined relative vaccine effectiveness (rVE) of aTIV versus QIV across 5–30% and seasonal attack rate across ±20% of the 8.0% baseline, and a break-even analysis identified the rVE threshold at which incremental costs equal avoided treatment costs. A probabilistic sensitivity analysis was also conducted to quantify joint parameter uncertainty.\n\nResults: At baseline (rVE 25%, attack rate 8.0%), Strategy I required $24.6 million in additional vaccine investment, with 52% offset by treatment savings, yielding a net budget impact of $11.7 million (+0.9% of total influenza-related healthcare expenditure). Strategy II required $54.4 million in additional costs with 57% offset ($31.2 million in savings), resulting in a net impact of $23.2 million (+1.8%). Strategy II prevented 535 deaths and over 15,000 hospitalizations—2.2-fold greater than Strategy I. The incremental cost of aTIV decreased with increasing transmission intensity, approaching cost neutrality during severe epidemic seasons. The break-even rVE at which aTIV becomes cost-saving was 44%, above central meta-analytic estimates (10–25%) but potentially attainable in severe seasons or specific subpopulations.\n\nConclusion: Introduction of aTIV into the Korean NIP is budget-feasible with substantial health benefits, requiring only a 0.9–1.8% increase in total influenza-related healthcare expenditure. At current rVE estimates (≤30%), aTIV does not achieve cost savings, but the additional fiscal burden remains modest. Strategy II offers superior health outcome value and is preferred when budget permits, while Strategy I provides a fiscally conservative entry point. The value proposition of aTIV is most favorable during severe influenza seasons.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Mathematics, Soongsil University",
    "Department of Pediatrics, Nowon Eulji University Hospital",
    "Division of Infectious Diseases, Department of Internal Medicine, Korea University Ansan Hospital, Korea University College of Medicine"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Eunha Shim"
    },
    {
      "affs": [
        1
      ],
      "name": "Byung Wook Eun"
    },
    {
      "affs": [
        2
      ],
      "name": "Won Suk Choi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5whd47am7zk87.bib",
  "cited_by": 0,
  "doi": "10.3389/fpubh.2026.1833971",
  "fulltext_url": "https://europepmc.org/articles/PMC13687060",
  "id": "5whd47am7zk87",
  "issns": [
    "2296-2565"
  ],
  "landing_url": "https://www.frontiersin.org/articles/10.3389/fpubh.2026.1833971/full",
  "language": "eng",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2713|Influenza Virus Research Studies"
    ]
  ],
  "openalex": "W7220933127",
  "pdf_url": "https://europepmc.org/articles/PMC13687060?pdf=render",
  "pmcid": "PMC13687060",
  "pmid": "42923232",
  "published": "2026-10-08",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/5whd47am7zk87.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:22Z",
      "native_id": "10.3389/fpubh.2026.1833971",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fpubh.2026.1833971/full"
    },
    {
      "first_seen": "2026-10-30T12:20:33Z",
      "native_id": "MED:42923232",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42923232"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2713|Influenza Virus Research Studies",
      "subfield": "epidemiology-public-health"
    }
  ],
  "title": "Economic analysis of adjuvanted trivalent influenza vaccine for older adults in the Korean National Immunization Program",
  "title_text": "Economic analysis of adjuvanted trivalent influenza vaccine for older adults in the Korean National Immunization Program",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:33Z",
  "url": "https://research.draconitic.com/paper/5whd47am7zk87",
  "venue": "Frontiers in Public Health",
  "versions": []
}