OBJECTIVES: The aim of this study was to evaluate the cost-utility of high dose quadrivalent influenza vaccine (HD-QIV) versus standard dose trivalent vaccine (SD-TIV) in the Brazilian elderly population (≥60y), from a public healthcare system perspective.

METHODS: A cost-utility analysis comparing HD-QIV versus SD-TIV was conducted using a decision tree model. The model estimates influenza cases, general practitioner consultations, emergency department visits, all-cause hospitalizations and deaths resulting from complications between vaccination strategy (HD-QIV vs. SD-TIV). The relative vaccine efficacy (rVE) of HD over SD against influenza cases was sourced from FIM12 randomized clinical trial and immunobridging studies whereas the rVE against all-cause hospitalizations was sourced from a meta-analysis that included data of ≥22 million subjects. The parameters as vaccine coverage, background mortality, hospital admission rates, proportion of cardiorespiratory hospitalizations were obtained from Brazilian DATASUS. Costs (expressed in Brazilian reais [R$]) were estimated from SIGTAP, DATASUS and other publicly available Brazilian sources. The model used lifetime horizon and 5% discount rate.

RESULTS: According to the model, switching from SD-TIV to HD-QIV could prevent 212,850 influenza cases, 36,625 visits to general practitioner, 19,242 visits to the emergency department and 170,002 episodes of hospitalization, in a population of 25,2 million elderly. The Incremental Cost-Utility Ratio (ICUR) of HD-QIV vs SD-TIV was R$23.969/QALY, being a cost-effective technology (Local willingness to pay threshold = R$40,000/QALY). Narrowing the population to older age groups, the ICUR turns more favorable R$17.458/QALY in the ≥70y population, and R$12.684/QALY in the ≥80y population.

CONCLUSIONS: Despite the incremental acquisition cost, this analysis suggests HD-QIV to be a highly cost-effective strategy versus SD-TIV, appealing policy makers to consider it as an option for elderly Brazilian population in the public healthcare system. Further research is necessary to assess HD-QIV impact considering other scenarios.