Economic evaluations of childhood influenza vaccination: a critical review.

The potential benefits of influenza vaccination programmes targeted at children have gained increasing attention in recent years. We conducted a literature search of economic evaluations of influenza vaccination in those aged ≤18 years. The search revealed 20 relevant articles, which were reviewed. The studies differed widely in terms of the costs and benefits that were included. The conclusions were generally favourable for vaccination, but often applied a wider perspective (i.e. including productivity losses) than the reference case for economic evaluations used in many countries. Several evaluations estimated outcomes from a single-year epidemiological study, which may limit their validity given the year-to-year variation in influenza transmissibility, virulence, vaccine match and prior immunity. Only one study used a dynamic transmission model able to fully incorporate the indirect herd protection to the wider community. The use of dynamic models offers great scope to capture the population-wide implications of seasonal vaccination efforts, particularly those targeted at children.