Virosomal influenza vaccine: a safe and effective influenza vaccine with high efficacy in elderly and subjects with low pre-vaccination antibody titers

In 14 clinical studies, various efficacy and safety aspects of a new virosomal influenza vaccine (Invivac ®) were assessed in 2865 subjects. The virosomal influenza vaccine fully complies with the Committee for Proprietary Medicinal Products (CPMP) requirement for immunogenicity of influenza vaccines. In particular, in a subset of subjects with low pre-vaccination titers (thus those persons who actually need protection by a vaccine), between 76 and 99% of subjects (dependent on age, health status and vaccine components) achieved protective hemagglutination inhibiting (HI) antibody titers after vaccination with the virosomal influenza vaccine. Acceptable frequencies of well-known local and systemic reactions were observed in healthy adults and risk subjects in clinical studies and in a post-marketing study population. These reactions were transient and generally not severe, and did not cause major inconvenience. In conclusion, Invivac ® is an efficacious and safe vaccine for the protection against influenza in healthy and chronically ill adult subjects. The vaccine is especially efficacious in subjects with low pre-vaccination immunity.