This Belgian study collected and analyzed an extensive range of Belgian data and developed refined modeling tools, which were applied to a very wide range of vaccination options. However, there are two main obstacles impeding simple, clear-cut specific advice on influenza vaccination for policy making.
On the one hand, the absence of information on how influenza vaccine would be added to the regional vaccination programs in Belgium, required modeling a wide range of age targets (including in children) and vaccine uptake options (5667 options were considered, which in turn multiplied when different assumptions on the costs of vaccine administration needed to be made). On the other hand, there are still many uncertainties on the influenza virus and its interaction with human hosts. Additionally, the clinical picture associated with influenza infection is not highly typical, which could lead to misdiagnosis, implying specific estimates of the disease burden of influenza are subject to substantial uncertainty, in terms of health outcomes, health care costs and health- related quality of life. Nonetheless, this elaborated study allows drawing a number of general conclusions, which are likely to aid decision-making. Indeed, the findings show that a large variety of influenza vaccination options for children and adults could be considered cost-effective, and some of these would even be cost-saving versus the current situation.