OBJECTIVES: Influenza affects millions of people worldwide, particularly older adults. Annual vaccination is the most effective measure to prevent this disease and its complications. This study assessed the cost-effectiveness and budget impact of implementing prophylaxis against the influenza virus using the high-dose quadrivalent influenza vaccine (HD-QIV) in individuals over 65 years of age in Argentina.

METHODS: We conducted a decision tree model from the perspective of social security and the private sector in Argentina, considering a hypothetical cohort of 1 million individuals. The comparators were standard-dose trivalent (SD-TIV) and standard-dose quadrivalent (SD-QIV) influenza vaccines for social security, and SD-QIV for the private sector. Model parameters were collected from official databases, comprehensive literature reviews, and expert consultations. Costs are expressed as USD 2023.

RESULTS: Compared with SD-TIV, the HD-QIV strategy resulted in an ICER of $2,369 with an increase of 0.0014 in quality-adjusted life years (QALYs)/person and an incremental cost of $4.12/person in social security, which is a cost-effective strategy for a cost-effectiveness threshold of $8,241. The HD-QIV strategy is dominant over the SD-QIV strategy for both sectors, gaining 0.0013 QALYs/person and saving $0.17 and $0.77 per person in the social security and private sectors, respectively. Introducing HD-QIV represented an average incremental per-member per-month (PMPM) cost of $0.02 for social security sector, slightly exceeding Argentina's high budget impact threshold ($0.0129 PMPM) estimated. In comparison, the average cost savings for the private sector were estimated at $0.04 PMPM. The PSA showed that the results are robust, and the HD-QIV strategy is cost-effective in 100% of the simulations for both sectors.

CONCLUSIONS: The introduction of HD-QIV in individuals older than 65 years is a cost-effective influenza prevention strategy compared with SD-TIV for social security and dominant compared to SD-QIV for both health sectors in Argentina.