Economic analysis of adjuvanted trivalent influenza vaccine for older adults in the Korean National Immunization Program
- 1Department of Mathematics, Soongsil University
- 2Department of Pediatrics, Nowon Eulji University Hospital
- 3Division of Infectious Diseases, Department of Internal Medicine, Korea University Ansan Hospital, Korea University College of Medicine
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.
Methods: 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.
Results: 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.
Conclusion: 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.
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BibTeX
@article{shim2026economic,
title = {{Economic analysis of adjuvanted trivalent influenza vaccine for older adults in the Korean National Immunization Program}},
author = {Eunha Shim and Byung Wook Eun and Won Suk Choi},
journal = {Frontiers in Public Health},
year = {2026},
month = oct,
doi = {10.3389/fpubh.2026.1833971},
url = {https://www.frontiersin.org/articles/10.3389/fpubh.2026.1833971/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Economic analysis of adjuvanted trivalent influenza vaccine for older adults in the Korean National Immunization Program
AU - Eunha Shim
AU - Byung Wook Eun
AU - Won Suk Choi
PY - 2026
DA - 2026/10/08
JO - Frontiers in Public Health
DO - 10.3389/fpubh.2026.1833971
UR - https://www.frontiersin.org/articles/10.3389/fpubh.2026.1833971/full
AB - 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. Methods: 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. Results: 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. Conclusion: 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.
SN - 2296-2565
ER -