OBJECTIVES: Severe influenza can be life-threatening and a significant burden for healthcare and society. Trivalent influenza vaccine provides limited prevention against often circulating influenza strains. The objective of this analysis was to assess the cost-effectiveness of replacing a trivalent influenza vaccine (TIV) with a quadrivalent influenza vaccine (QIV) in the national immunization program (NIP) in Colombia.

METHODS: A decision-analytic static cost-effectiveness model was used. The population was stratified into age groups. Costs and outcomes were estimated for an average influenza season, based on observed rates from 2013 to 2019. Costs are expressed in 2018 USD$ using an exchange rate of COP$2956 per USD$1. Robustness of results was tested in the sensitivity analyses.

RESULTS: During an average influenza season in Colombia replacing TIV with QIV would avoid 5,005 influenza cases (including 1,765 General Practitioner consultations and 711 Emergency Department visits) and 651 hospitalizations mostly in children ≤4 years old. It would prevent 43 influenza associated deaths, mostly in the population ≥65 years. This would lead to savings of $673,279 from third party payer perspective or $1,831,723 from societal perspective, where productivity loss due to illness (454 days saved) is considered. These savings could partially offset additional costs of QIV of $8,039,649. The incremental cost-effectiveness ratio (ICER) gained with QIV would be $13,466 and $11,342 per additional quality adjusted life years (QALY) from third party payer and societal perspective, respectively, which is below the willingness-to-pay threshold of three GDP per capita. For the ≥65 years group, ICER was much lower reaching $4,710 and $2,515 per QALY from the payer and societal perspective, respectively. The main drivers influencing the ICER were vaccine efficacy against the B strains and level of cross-protection.

CONCLUSIONS: A switch from TIV to QIV in the NIP is expected to be cost-effective for the current target populations in Colombia, especially for older adults.