Cost-effectiveness of cell-based quadrivalent versus egg-based trivalent influenza vaccination in the Brazilian National Immunization Program

Abstract

Objectives: This study aimed to estimate health and economic outcomes associated to cell-based quadrivalent influenza vaccine (QIVc) versus current trivalent influenza vaccines (TIVe) for seasonal influenza prevention in the Brazilian National Immunization Program (NIP), from the societal and public payer perspectives. Methods: A 1-year static decision-tree model based on literature was used. 54,071,642 total vaccinated individuals in 2019 were considered; influenza subtype circulation was based on Brazilian epidemiologic data (2009-2019). TIVe vaccine effectiveness (VE) was extracted from a published meta-analysis and QIVc relative VE from an international retrospective observational study. A/H3N2 egg-adaptation and B mismatch to recommended strain were gathered from international retrospective sources. Resource use was obtained from real-world studies. Inputs were adjusted to influenza subtype and multiple age groups with Brazilian literature. Unit costs were retrieved from published standard tables in 2019 Brazilian Reais (BRL). Results: Replacing TIVe with QIVc, can annually avert symptomatic cases (452,065) and reduce outpatient visits (118,735); hospitalizations (15,466), deaths (2,753), overall medical direct costs (-BRL 46,677,357) and indirect costs (-BRL 59,962,135). The annual number of quality-adjusted life-years (QALYs) could be increased by 96,129. Base case results from the payer perspective show an incremental cost-effectiveness ratio (ICER) of BRL 17,293/QALY gained and from the societal perspective the ICER obtained was BRL 16,669/QALY gained. Using the Brazilian Gross Domestic Product (GDP) as a threshold (BRL 34,533/ QALY) switching TIVe with QIVc in the NIP can be a highly cost-effective strategy, leading to a high QALY increment and preventing medical and indirect costs. Conclusions: The use of QIVc by the NIP has the potential to be highly cost-effective in the payer and society perspective.