Adjuvanted influenza vaccine for the Italian elderly in the 2018/19 season: an updated health technology assessment

Background: The elderly, defined here as subjects aged 65 years, are among at-risk subjects for whom annual influenza vaccination is recommended. For the 2018/19 season, three vaccine types are available for the elderly in Italy: trivalent inactivated vaccine (TIV), adjuvanted TIV (aTIV) and quadrivalent inactivated vaccines (QIV). No health technology assessment (HTA) of seasonal influenza vaccination in the elderly has previously been conducted in Italy. Methods: An HTA was conducted in 2017 to analyze the burden of influenza illness, the characteristics, efficacy, safety and cost-effectiveness of available vaccines and the related organizational and ethical implications. This was then contextualized to the 2018/19 influenza season. Comprehensive literature reviews/analyses were performed and a static mathematical model developed in order to address the above issues. Results: In Italy, influenza is usually less common in the elderly than in other age-classes, but the burden of disease is the highest; >10% of infected elderly subjects develop complications, and about 90% of all influenzarelated deaths occur in this age-class. All available vaccines are effective, safe and acceptable from an ethical standpoint. However, aTIV has proved more immunogenic and effective in the elderly. Furthermore, from the third payer’s perspective, aTIV is highly cost-effective and cost-saving in comparison with TIV and QIV, respectively. Nevertheless, vaccination coverage needs to be improved. Conclusions: According to this HTA, aTIV appeared the vaccine of choice in the elderly. HTA should be reapplied whenever new relevant data become available.