Cost-effectiveness analyses of quadrivalent influenza vaccinations in the general European population – a systematic review

Influenza infections affect around 20% of the population annually, generally causing a mild viral syndrome, but occasionally leading to severe complications or death. Influenza vaccines, with quadrivalent influenza vaccines (QIV) as the newest generation, decrease the likelihood of infection and complications. Because both influenza infections and vaccinations impose costs on patients and on the broader society, the health gains of vaccination programs should be weighed against their financial impact. This review summarises the literature on cost-effectiveness analyses for quadrivalent influenza vaccinations compared with non-vaccination, in the general European population since 2012.
We conducted a systematic review of the literature on cost-effectiveness analyses that compared quadrivalent influenza vaccination with non-vaccination.
The eight included studies found that QIVs were cost-effective in 18/19 analyses at a willingness-to-pay threshold of 35 000 euro/QALY and in 15/19 analyses at 20 000 euro/QALY. Herd immunity was a major factor, as a large part of the observed cost-effectiveness gains occurred not in the targeted population for vaccination (children) but in the generations of their (grand)parents .
This review suggests that vaccination programs with quadrivalent influenza programs are cost-effective compared with no influenza vaccination, regardless of the modelling assumptions. Their implementation should always be based on multiple factors, such as cost-effectiveness, the latest recommendations on optimal effectiveness for each influenza season, and ethical considerations. These results may have been influenced by the clinical and epidemiological validity of the data used by the included studies and the limited number of included analyses, most of which were industry funded.