Towards an epitope-based human vaccine for influenza.

The conventional, currently available vaccines against influenza virus, though quite successful, suffer from a few shortcomings; one major limitation is their restriction to the specific strains that are included in the vaccine. We review herewith some of the more recently developed influenza vaccines and further describe our own results on the design of epitope-based vaccine for human use. In this vaccine, a combination of B- and T-cell epitopes are individually expressed within an immunogenic molecule--salmonella flagellin--and the resultant recombinant flagella serve both as a carrier and as an adjuvant. The mixture of recombinant flagella expressing the appropriate epitopes was administered to young and aged mice as well as to human/mouse chimera model in which human PBMC are functioning within the mice body. Intranasal immunization in all these animal models led to effective protection against challenge infection with different strains of influenza virus.