Potentiating the effectiveness of influenza vaccination by a combined immunostimulation with P40 immunomodulator: an experimental study in mice.

Influenza vaccination is highly desirable in view of the epidemic character of this infection and of the severity that it can assume in high-risk and in elderly persons. Its effectiveness varies from 40-90%. Moreover, strains can undergo an antigenic drift in the course of an epidemic. Consequently, reinforcement of the immunogenicity of vaccines is required for achieving a more complete immunization coverage. Combination of an immunomodulator, the C. granulosum-derived P40 fraction, with influenza vaccine resulted in significant potentiation of vaccine immunogenicity. In addition to its adjuvant action, the P40 is also likely to exercise a protective effect by stimulating the non-specific immune defenses of the organism.