Cost–effectiveness analysis of quadrivalent influenza vaccine in Spain

Amos García,Raúl Ortiz De Lejarazu,Jordi Reina,Daniel Callejo,Jesús Cuervo,Raúl Morano Larragueta

doi:10.1080/21645515.2016.1182275

Abstract

ABSTRACTInfluenza has a major impact on healthcare systems and society, but can be prevented using vaccination. The World Health Organization (WHO) currently recommends that influenza vaccines should include at least two virus A and one virus B lineage (trivalent vaccine; TIV). A new quadrivalent vaccine (QIV), which includes an additional B virus strain, received regulatory approval and is now recommended by several countries. The present study estimates the cost-effectiveness of replacing TIVs with QIV for risk groups and elderly population in Spain. A static, lifetime, multi-cohort Markov model with a one-year cycle time was adapted to assess the costs and health outcomes associated with a switch from TIV to QIV. The model followed a cohort vaccinated each year according to health authority recommendations, for the duration of their lives. National epidemiological data allowed the determination of whether the B strain included in TIVs matched the circulating one. Societal perspective was considered, costs and outcomes were discounted at 3% and one-way and probabilistic sensitivity analyses were performed. Compared to TIVs, QIV reduced more influenza cases and influenza-related complications and deaths during periods of B-mismatch strains in the TIV. The incremental cost-effectiveness ratio (ICER) was 8,748€/quality-adjusted life year (QALY). One-way sensitivity analysis showed mismatch with the B lineage included in the TIV was the main driver for ICER. Probabilistic sensitivity analysis shows ICER below 30,000€/QALY in 96% of simulations. Replacing TIVs with QIV in Spain could improve influenza prevention by avoiding B virus mismatch and provide a cost-effective healthcare intervention.

Highlights

Seasonal influenza is an acute viral infection that circulates worldwide and spreads from person to person
Over a lifetime horizon (100 y) evaluation of influenza vaccinated age-cohorts, using quadrivalent vaccine (QIV) would result in 40,000 additional quality-adjusted life years (QALYs) gained compared to the use of trivalent vaccines (TIVs), with an increased cost of 350 million €
Our base case results indicated that the QIV would deliver substantial health benefits from the National Health System (NHS) perspective by further reducing the number of symptomatic influenza cases, of medical visits, of hospitalizations for complications, and of deaths as well as of work absenteeism, compared to TIV

Summary

Introduction

Seasonal influenza is an acute viral infection that circulates worldwide and spreads from person to person. It can affect any age group, cause annual epidemics and represents a serious public health problem, due to the severity of the illness and the number of deaths in high risk populations. There are three types of seasonal influenza viruses: A, B and C. Type C influenza cases occur much less frequently than types A and B1 but type A influenza viruses cause most influenza infections. Type B infection is frequent in children and young adults and is the predominant virus to cause epidemics every 2–4 y.2. Type B infection is frequent in children and young adults and is the predominant virus to cause epidemics every 2–4 y.2 Type A and B infections produce similar clinical symptoms, hospitalization rates and rates of admission to Intensive Care Units.[3,4]

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