This invention generally relates to immunogenic compositions that comprise an RNA component and a polypeptide component. Immunogenic compositions that deliver antigenic epitopes in two different forms—a first epitope from a pathogen, in RNA-coded form; and a second epitope from the same pathogen, in polypeptide form—are effective in inducing immune response to the pathogen. The invention also relates to a kit comprising an RNA-based priming composition and a polypeptide-based boosting composition. The kit may be used for sequential administration of the priming and the boosting compositions.