Protein Vaccination Directs the CD4 + T Cell Response toward Shared Protective Epitopes That Can Be Recalled after Influenza Virus Infection

Abstract

Most current and new influenza vaccine candidates consist of a single influenza virus protein or combinations of influenza virus proteins. For these vaccines to elicit CD4 + T cells that can be recalled after infection, the peptide epitopes should be shared between the two modes of confrontation. Recently, questions regarding the relatedness of epitope selection by influenza virus infection and protein vaccination have been raised. However, the studies reported here show that the specificity of CD4 + T cells elicited by protein-based vaccines overlaps that of T cells elicited by infection and that CD4 + T cells primed by protein vaccines are recalled and contribute to protection of the host from a future infection.