[Seasonal flu vaccination for older people: Evaluation of the adjuvanted vaccine. Positioning report].

Flu is a major public health problem, particularly for older people, and creates an important clinical and economic burden. A high mortality rate was reported in Spain during the period 2015 to 2016; 3,101 serious cases were hospitalised with a confirmed diagnosis of flu, of which 11% died (352 cases). Furthermore, financial and health costs are greatly increased by the complications of flu; people aged over 65 years represent approximately 64% of the total costs. Seasonal flu vaccination is the fundamental strategy, as demonstrated by cost-benefit and cost-effectiveness studies. A priority objective is to improve the vaccine's immune response and the search for and inclusion of adjuvants and immunostimulants in vaccines is a major line of research. This positioning report evaluates vaccination for older people and the importance of the adjuvanted vaccine in the elderly in strengthening immunogenicity, by means of a critical review of the literature based on the best evidence available on its immunogenicity and effectiveness, and an economic assessment.