MF59-adjuvanted subunit influenza vaccine: an improved interpandemic influenza vaccine for vulnerable populations.

Influenza is a highly contagious respiratory disease associated with substantial morbidity and mortality in vulnerable populations, especially the elderly. Influenza viruses are unique in that they undergo small mutations and antigenic variation in their hemagglutinin and neuraminidase genes. Owing to the senescence of the immune system, the ability to mount novel immune responses may be particularly compromised in older people. Fluad (Novartis Vaccines), an MF59-adjuvanted subunit influenza vaccine, was formulated in order to achieve greater immunogenicity in those groups who need a higher protection than that brought about by conventional vaccines. This article summarizes the main characteristics of MF59-adjuvanted subunit influenza vaccine, the clinical effectiveness data that have been generated in recent years and future developments.